Coins is the main game currency which is used when you collect rent from properties or collect for various quests, crops, etc.
You must use energy to perform all tasks on the frontier. Energy regenerates at a rate of one point every three minutes.
Once you begin a new account, log in only with email, no social networks. Once you progress a few levels there is the option to visit other towns. Click it and visit "nearby town". Return from it to your town and you should now have unlimited energy until you exit out of the application.
You have the option to see the towns of other players if you wish and to ask them for energy once every 24 hours.
In order to visit neighbors you must be signed into at least your Facebook account or one of your other supported social network accounts.