Yeah, the proper way to explore is to save up a ton of turns and then explore 40+ turns all at once. That way you get to keep a high acre/explore for all 40 turns. If you explore in, say, 5 turn increments instead, your acres/explore will drop a few acres each increment, and you'll end up with less acres overall.

As far as army goes, I think the best way for a noob to start out is to explore to 3k acres with 50bpm, maintaining at least 10-20 turrets per acre all along the way. After that, aim for a 1:1 ratio of Jets:Turrets. And then try to keep your Troop and Tank numbers equal to 10% of your Jet number. That will give you enough offense to give you some experience attacking at least once per day, but not so much that it encourages topfeeders.

Maintaining a small Troop+Tank count will help give you insurance against griefers, which can be very difficult to deal with when you're a noob. As you get more pro at locating and avoiding griefers, you can decrease your Troops+Tanks in favor of more Jets+Turrets.

Make sure to get 2 defensive allies of about equal size to you after you hit 3k acres. If you outgrow your allies by more than 50% then it's probably a good idea to drop them and try to find somebody new. Don't bother with offensive allies until you get more experienced with the game, if you don't use them properly its easy to get exploited.