I have never had much success with miracle-grow stuff. I put one grow-spike in with one of my wifes plants and it killed her plant in about a week...lol I am using this potting soil (organic) called PRO-MIX. It is specially formulated for growing vegtables. It looks like a part-mulch/soil mixture with fertilizer added. I started from seeds on Feb 15th and most of my tomatoes plants have 4 leaves now. My few pepper seedlings are close to a week
old and about 1" tall. I transplanted mine (tomatoes) into
those white 8oz styrofoam cups. Just remember to put a few drain holes along the base of the cup.

I start seed without any pretreatment and it grows fine as long as the surroundings are reasonably warm. Lots is written about how to enhance growth, but most seeds will grow fine without the extra care. It can be fun to try to speed things up, but don't get too worried about things. Plants want to grow.

I grow peppers in pots 12 inches across and 12 inches high.....also larger and smaller pots. The larger the pot the less often you need to water and the easier it is to regulate moisture. The 12 inchers worked fine for average sized plants as long as I watered daily during dry, hot weather, and didn't want to go on vacation. If I went away, I needed to have someone trained and willing to water for me. I may look into rigging up some kind of self watering containers this year to save time and get away from the daily checkups. The 12 inchers were also a reasonable size to bring in to overwinter. Overwintering usually brings aphids and some other pests inside that get out of hand without the outdoor natural predator control. With fast growing varieties it may be easier to grow new plants each year....but it is fun to play in the dirt during the winter....even fun to squish a few aphids now and then. And the bigger plants set pods earlier in subsequent years.

I potted with ProMix that I got at Home Depot. Not sure what other stores have. As long as you avoid soil and stay with a container mix you should be okay. I've fertilized with a variety of things including Miracle Grow. Follow label directions or go half of the recommended container amounts. I mix 1 level tablespoon MG into a gallon of water and use it now and then. Haven't had any trouble with it. Most of the time I just use tap or rainwater. My fertilizer "schedule" is usually based on how the plants look. If the leaves aren't looking as green as normal, I figure it's time to fertilize. However, if there is alot of rain and the potting mix stays very wet you will see yellowing that doesn't signal you need nutrients. You need to let the potting mix dry out some and the plants will green up again. I've not added bone meal, but our water is hard and contains a good amount of calcium. Not sure if that takes the place of bone meal or not, but I haven't been bothered with blossom end rot.

Peppers seem resiliant to me. They grow well without alot of fuss, and that is a good kind of plant for me.

Welcome to the pepper obsession!