Turn the engine over slowly, and make sure it's smooth and free. If you have a bushed engine, you are in luck, probably won't need a thing. Take the battery packs out of the radio(s), and look at them to see if there is any corosion. (green or black crud) Check each cell with a multi-meter to make sure you don't have any bad cells. Charge them for 16 hrs. on the wall charger. Flush out the tank if it's EVER had fuel in it, and inspect the fuel lines. Drop a few drops of fuel into the intake, and turn the engine over several times, this will help to loosen any gummy old cator oil.
Range check the radio by putting the Tx antenna down, and walking at least 100' feet away.
Get someone who is proficient to help you foir the first couple of "re-introduction flights".
Ask a lot of questions here, and good luck. Let us know the outcome.

Jetts