I'm just level 4 on the Haikou Region, and I leveled up my treecko to sceptile in the Jataro Region (I didn't know that you can't use high level pokes on the new region). Now my treecko won't obey me and my lowest level poke aside from treecko is tyranitar lvl 60. What do I do? can I get a reset?
You cannot reset, you will have to fight gyms and get badges to raise the level of the Pokemon you can use. You can also catch other lower level wild Pokemon.