Your engine will be fine so long as you got water out. The electronics are most likely to damage in this situation. Don't power them on for atleast 48 hours if they got wet. Go to Lowes and get a good set of ball/round tip Allan wrenchs in standard and metric. Nothing crazy or fancy is needed. If you want to spend the extra money then T handle Allan are nice, but more important is getting a good range of sizes with ball ends. The rounded tips let you use them at an angle. Other then that buy tools as you find you need them. Save your money and spend on a good set of RPM A-arms and for spare parts as you may need them. Tools I find I need frequently but you may or may not need:
Needle nose players
Punch set
Small channel locks
Soldering iron
Tweezers
Small side cuts (dykes)
Spares:
Glow plugs
Glow driver
A arms
Air filter foams
Variety of shock oils
After run
Small cans of wd40
Zip ties
Batteries
Just some of the stuff I keep in my tool box for outings. This hobby will take enough of your money, don't be in a hurry to blow it all at once. I love my cars, but my wife and wallet do not. Hope your car turns out fine, traxxass are pretty tough and when they break they are easy to fix.