I would start with a rug, pull the sofa forward and put a sofa table with a lamp behind it and get a console for under the TV to anchor it

What a cute room, love the sliding glass doors. I would do the tv wall in a rich color (Earthy hues, like a nice brown would be great with your patio view...then pick a color combo you like for accent pieces (area rug, throw pillows, lamps, art, etc.) You could also do a pop of really pale blue behind your couch & it would balance the wall behind the tv. Either way, pick colors that you like & it'll be perfect! Good luck and I hope you post a pic when you're done!