First truck, First Toyota, a couple questions

Heyy everyone, Just bought my first truck (2000 ext cab white 3.4 L Tacoma ) and did a few mods myself . I put a pro comp 6'' lift on it, 33 '' pro comp x-terrains on 16 '' eagle alloys, cold air intake, 7 inch LCD, speakers subs tweeters etc. tinted windows, l.e.d. light strips etc. custom front and rear steal bumpers with integrated lights/turn signals I am only 16 so i cant drive it yet but the time comes close and I'm just wondering with all the mods I did if there is anything I should worry about when i start driving it . Iv had to pay for everything by myself so id like to catch any problems as soon as i start driving it. and does anyone know what it would cost to put 4:10 gears in it ?? thanks in advance !!