Welcome to the hobby and to the forum.
I would start by downloading or printing a copy of the instruction manual. It's saved as a sticky at the top of the sub forum but here's a link.
https://www.teknoforums.com/threads/tekno-rc-sct410-3-manual-setup-sheet.10/
If you don't already have a set I would start with a decent to good set of hex drivers to reduce the risk of stripping screw heads during maintenance/tear down/rebuilds.
Give it a good look over for any obvious bent or broken bits. Remove the shocks and check that the suspension cycles smoothly with no binding. I think it would be worth creating a setup sheet to document what you're starting with to compare to the kit setup per the manual.
If it came with electronics and you have a tx, rx, battery and charger I would charge a battery and take it for a Sunday drive. See if it tracks straight, makes any crazy noises or lets out the smoke or flames.
If you have any questions post them up but the most important thing you need to do is have fun with it.