Hello every 1 . I am new to drifting and I just baught a TC4 and was wondering what do I need to buy and how do I lock the rear end ?

If it has a regular gear diff, fill it with hardening putty, JB weld, plastic wood, whatever you can get your hands on to lock those gears down forever.

what about a spool or a diff locker ?

That's the best way to do it, but not the cheapest.

i have used the original expanding gorilla glue to lock a few diffs. Just make sure to shove the axles/junk axles to fill the holes or you wont be able to get the axles into the holes because gorilla glue expands like crazy! Also dont fill the diff space full (found out the hardway) and then I used a vise to clamp the two axles so they couldnt expand out of the diff and let it sit for about two hours...I havent tried it under power yet (stock e10 speed controller cant handle 9t) but it fells really locked.