Especially if you have never built a layout before, I would suggest you build one layout, then the other. They both sound great, but trying to do 2 at the same time could be tough. First off, you will make a bunch of "mistakes" along the way.......some will be things that are "OK" but you wish you had done them differently, others will be major "oops" that will need to be fixed to get the layout to work properly. It's better to do your learning on the first layout, THEN do the second. Also , there is cost.......at 12, I'm guessing you don't have unlimited funds (none of us do) so I'd try to spend your money on just one layout at a time. Nothing is more frustrating than a half finished layout, let alone TWO half finished layouts. AT LEAST do all the track and wiring on one before you start the second.......at least that way you can start running trains. Ask all the questions you want. Good luck!
