vehicle doesnt move

😟hi.

i created a vehicle (tractor) and a child called seat. i can sit but it doesnt move, i tryed the last 4 days and 100 scripts, but i sit, press w and i walk again, but the w means it should move. sorry my english is not very well, but im a stupid German an why doesnt it work, any ideas? i tryed interaktiv, animated too. all i want is driving arround with my tractor ;-)