Thick newbi needs help

[jenky]

Bought a s/h dex410 with is awesome. Everything ready to go just had to fit my own radio gear. Got a s/h dx3 and reciver.
Put them in tonight but the car will only run forward, when I try to reverse it locks up like a brake but no reverse.

No idea what I'm doing and have no idea were to start.

Has a 100a trackstar esc fitted but don't have a program card for it and no idea about changing setting as this is the first modern car I've had.

Only ever had the old tamya with a sevo speed controller.

About to give up lol and cry.