From EUW looking to change server and i have some questions

Hey guys, I have always dreamt of reaching challenger and getting that beautiful border. The thing is im in my senior year of high school and therefore i have to focus 100% on school and can only play a couple games a day. So i was thinking about making a server transfer, and then reach challenger on another server for the rewards. But how does this work. Im from EUW, and can i just transfer back and forth? Do i keep all my champs, my skins, my elo(d3), and which server is the "easiest" i heard it was russia or TR? And do my rewards follow me back when i transfer again to euw? tyvm i apologize if my english is bad