Congrats on the Tower trainer. I learned on one, along with real-flight, myself last year. The biggest difference I found between the real-flight Nextstar and the Tower Trainer is that the TT seems more lively in real life. I made no modifications to my control surfaces on my TT, however it responds faster and with more authority than the G3 Nextstar. When using the simulator, make sure you're using the version of the Nextstar that does not have the crash avoidance system active. That is definitely a crutch you don't want to get used to.

Lastly I'll also recommend that you get assistance from a local flying club and instructor. I would never have successfully maidened my trainer without some experienced help.

good luck & safe flying!