This is long but I need someone to help and let me know if this could be used as a descriptive paragraph?

your paragraph is somewhere between expository and descriptive. You explain 3 advantages of being the youngest child(as far as I could tell) but then you describe some parts well. If you want to make this a wholesome descriptive paragraph, put in more imagery. Describe it in enough detail so that I can imagine it; don't go off naming different brands, items, or activities. And you typed "gobs off" when you should have typed "gobs of".