Hi micro-rc-guy,
ok, I try to answer you (sorry about my english writing ;-) )
1, the experience
you shoud have fun to assemble small toys, thats all (all the other is lerning by doing or asking here)
2, the best way to start
The best way to start will be to modify a 2axle "Faller Car System" Truck. This one comes with a driveline and steeringaxle so you have only build in the rc- parts (like reciver, battery, servo, speedcontroler).
I think a Unimog as your first steps may be a little too small. A better solution is a MAN 5to or something else in this sice.
3. the Tools,
A pair of tweezers, some small tongs, a knife, maybee a magnifier and a clean desk with a good lamp.
I suggest you to start with a "simple" "large" 2axle truck. So you will make the first experience without havy problem.
The second one will be a smaller one, maybee an Unimog with lights,.....
best regards
Thorsten
www.mikromodell.de