You could begin with some solar lights at each corner of the yard. They could be added directly to the fence posts or added to treated boards attached to the posts. Do you want a flower garden or a veggie garden or both? Adding metal hanging brackets to any'/all of the fence posts would enable you to add baskets of flowers or strawberry plants or herbs and spices and/or vine tomato plants or other veggie plants without planting anything against the fence that would require digging near the fence (potentially loosening the fence posts) or that might hold moisture at the fence that could decrease the life span of the fence -- and yet still soften the look of the fence with greenery. You could also invest in some 4"x4" treated posts and add solar lighting and/or hanging brackets for hanging baskets for flowers or bird feeders or bird houses or even holiday decorations. If you cut any 8' post to 6' (to make them more practical) and as long as you keep each one balanced (same weight hanging pots on each side), you can make these portable Instead of putting them in holes in the ground fixed in one position. In January, thrift stores likely will have large plastic holiday tree stands cheap that can hold 4"x4" posts. You can drill a few holes in the bottom and use the stand to hold your post. Or, you could create a stand for your post by adding four 16" 2"x4" boards, one facing each direction, to the bottom of the post. You have a slope in your yard, You could create a nearly level place at the bottom of the slope adjacent to your fence for your playground equipment (swings for both children and adults would be my priority) by adding a short knee wall across at least part of it to create an upper and lower terrace to make a distinction between the slope and the level area -- a knee wall just high enough that it could also be used as seating. Such a level place could be used for horseshoes or volleyball or badminton or croquet or ring toss, etc. Any dirt you dig out below the location of any knee wall could be tossed above it to level another place just above the knee wall for a veggie garden if you have a level room for your picnic table and chairs adjacent to your house. https://www.google.com/search?q=small+short+terrace+walls+in+back+yard&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiPodmPtKzmAhUDhuAKHb5gBUsQ_AUoAXoECA4QAw&biw=1328&bih=617#spf=1576026477049  You could keep the slopes on the sides of the yard adjacent to the fence rather than disturb the fence posts -- and, if it snows, for a slide or, in summer, for a summer water slide. https://www.google.com/search?q=images+backyard+summer+water+slide+on+slope&tbm=isch&source=univ&sa=X&ved=2ahUKEwjdyc7UtKzmAhUxU98KHYnVBsIQsAR6BAgKEAE&biw=1328&bih=617#imgrc=eK3LWKHahl2VcM:&spf=1576026621516 How much nearly level space you have adjacent to your home for your patio for your backyard BBQ grill or do you need to use part of the sloped or lower more level area adjacent to the fence for that?. Whatever you do, don't "crowd" the back yard and create a cluttered look.

You'd probably need to show the view in each direction. (Stand at center of the yard and take slightly overlapping photos of a 360*view -- without changing camera locations between any pictures.) And you probably need to show an outward bound view of 3/4 of the yard as taken from the patio center. (Again, in slightly overlapping pictures while the photographer does not change locations, but pivots.) And you'l need to show as close up as you can get of the yard from Google Satellite.

I don't think you have enough room on the side of your house for a fire pit. This Houzz ARTICLE recommends a 12-14 ft diameter from the center of a fire pit. That's 6 ft minimum from the center of the fire pit. Plus, I doubt your neighbors would appreciate the proximity to their house, and you could be violating city code. Much better to put the fire pit closer to the center of your yard. I did a mockup of what this might look like. You can still place a patio on the right side of your house with seating. And, instead of building a pergola, consider a shade sail that attaches to the fascia of the gable and then to a pole at the edge of the deck.

Concrete stain can really improve the look of concrete flooring. But you have to make sure your concrete is not already sealed. Since your concrete surrounds a pool it's possibly already sealed, and that sealer would have to be removed first. Below is a photo of unsealed (left) and sealed concrete that just had water poured on it. Hopefully you can see how it beads up on the sealed concrete. As to furniture around this pool, it's easier to fit chairs and loveseats into tight spaces. Outdoor furniture is often smaller than indoor furniture. Most indoor loveseats measure 3' deep x 5' wide. Sofas start around 7' wide. An outdoor loveseat may be as small as 2.5' x 4'. Nonetheless, your space doesn't seem that small. I think you should measure the area across each end from house to outside wall and from the pool edge to the outside end wall. Draw those measurements onto paper so that 1' equals 1" on paper. On another piece of paper draw the outlines of any furniture pieces you have or want to buy to the same 1' equals 1". Take a tape measure with you when shopping in case the size of furniture is not listed. Most online outlets will list sizes. Label each furniture piece and cut it out. Now you can move the pieces around to get the best fit and use of your space, but remember that where people walk there should be 42" or more width, but 36" to enter a seating area is OK. It would be great to find a tall cabinet to hold tools and chemicals for the pool, but most I've seen are under 6'. In the meantime, a folding screen could work to hide those items. Larger pots don't dry out quickly and are less likely to get knocked over, but terracotta pots get really heavy. In addition to plastic there are fiberglass and resin planters which can look like terracotta, glazed porcelain, wood, stone and metal. Here are some resin planters. Annual plants are the easiest to take care of and provide lots of color. If your winter is mild you can use cool season annuals, like snapdragons, pansies, pinks and sweet alyssum, to fill pots from late fall until mid spring.