I'm not sure about the answer to your second question, but here's my answer for the first (mind you, it may not be very good, I've been playing for only 1.5 months):
1) Collect resources
As you've just started, you're going to need resources to build stuff you really need, like a barracks, because the Force of Terror is soon going to start troubling you. Other players can't bother you until your base is level 10, so don't worry about that just yet.
2) Capture land
You should start capturing land around yourself. Your aim is to get a high level land. When a land is within 500 metres of you, you can level it up from where you are, but otherwise you'll have to go to within that land's area and press the 'capture land' button to level it up.
As you level it up, it will cover a larger area and this enables you to collect resources in your area easily. At level 2, your land also unlocks two new buildings. It unlocks a lot more buildings and features at level hundred. However, you'll need to build and upgrade things at some point to level it up. You can't have a level eleven building without atleast one building - the game won't let you.
You can also merge lands with your own lower level lands, buy lands from others or take over them in a war.
3) Scan daily
You see that 'scan' tab in the end on the navigation menu? It's a pretty useful feature. You can scan ten barcodes everyday for money and supplies. On lucky days, you can get a bunch of money. Usually, one barcode will give you under ten coins or one supply package, but you may get fifty coins or ten supplies from one! They're also your only source of power-ups until you build a supply factory. So I recommend scan ten barcodes daily. They shouldn't be hard to find, most items bought from stores have them. Books, pens, drink bottles, games, etcetera are good places to look.
That's about it for the very basics. If you want to learn more, I recommend reading these forums sometimes. Perhaps a question you had has already been answered. Or perhaps you just wanted to know more about what's planned for the future. Everything's here.