When a muslim is praying which direction does their feet point or face? th right side or just flat behind u?

i dont get it. im ten i pray all 5 prayers and im still having confusions and questions. When a muslim is praying which direction does their feet face or point to? right side or just flat down behind you? another question is when you are praying when do u make du'aa and say say subhlah,alhumdulillah, and allah hu akbar? i do it when i finish fardh but other ppl dont. i know when you rise up straight after you touch your knees you dont say allah hu akbar but its a habit for me i just wanna know if it is ok if u do say allah hu akbar please gimme answers as soon as possible im a muslim in need even tho im about to go to musjid.