Giavanna, I think your best best is to first settle on a look you're going for. Go through Houzz photos (do a search on Open concept living rooms) and create an ideabook of things you like. Do you like modern styles? Traditional styles? It looks like you have kids, so family friendly will likely be important. I think we need a bit more to go on before we can give you good advice.

The table top in your inspiration pic caught my attention. It's not the usual furniture showroom table top. I really like this cedar "countertop" and was wondering if something like it might work as a table top or as a top of a rolling cart island that could work as kitchen prep space and/or guest dining if not as a table. http://www.devoswoodworking.com/designing-wood-countertops/wane-edges.html Legs could be bought separately. https://carolinalegco.com/products/x-metal-table-legs-set-of-2-modern-industrial-legs-custom-sizes-available?variant=32186224640097&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&utm_term=&utm_campaign=DR_PLA_Smart_200%25&utm_source=adwords&utm_medium=ppc&hsa_acc=7051262680&hsa_cam=9915659242&hsa_grp=103137792649&hsa_ad=432122759881&hsa_src=u&hsa_tgt=pla-296303633664&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gclid=EAIaIQobChMI6p_wwNPU6gIVgbbICh0T8w-jEAsYAyABEgIkX_D_BwE

You've received some great suggestions. I think lighting is key. I would eliminate the bare bulb floor lamp by the fireplace and find some attractive lamps with shades. One for the console table, a floor lamp for the lounge chair and a table and lamp for the arm end of the sectional. I would budget to have an electrician come in and move the boob light in the dining room to center over the table once you've reduced its size. Change that to a lovely chandelier. If you can't afford all of that, you can swag a chandy from that connection to a more centered position as in the kitchen below.

It's a beautiful house! I know this isnt your arrangment of furniture but just some reminders: Firstly, the sideboard/dresser infront of the windows has to go. It's way too large and blocking the view. Those windows are beautiful and would look great with proper window treatments (your option if you want treatments), we can get to that after we settle the sofa in.  Since you have an angled fireplace, you will have to work with what you have. I do not recommend angling furniture sideways. It never looks good and it makes the space less efficient most importantly. The couches in the photos currently are a little too drab and clunky for the atmosphere of the house.  You can have comfy, child-friendly furniture and still not skimp on design either. I will create a mockup of this room and show furniture placement and sofa possibilities. But before we begin, What is your preferred style for this living area? Or what goals do you have for how you want it to look, stylewise-modern, luxury, country etc. Inspiration photos will help you narrow down your options because at this point you have a clean canvas once all the previous owners items are gone