Congrats and welcome to the forum!!!
Jump on the Vegas page Nevada Jeep Forum - Jeep Wrangler Forum
Loose bunch we post up runs and other things so hang out there once in awhile.
Stock JK auto or stick is very capable and have wheeled with both the only thing the auto needs is a transmission cooler for the longer climbs they seem to heat up a bit. Hopefully yours will come factory installed if not check with your dealer.
Lift can be done without voiding your warranty. Call the service dept at Chapman in Henderson look for Derrick Goern and he will fill in all the details.
Also if your are looking to go wheeling check out the Desert Wranglers in Google go to the home page and see if there charter fits what you want to do with your Jeep. If so join no cost no meeting requirements just have a wrangler and enjoy it.