Battle recommendation

My terracore battle recommendation is to contribute even the smallest fraction of a scrap to the Oceanea research on the explore page. Having a little bit of favor makes a big difference from having none when it comes to battling.

You'll also want to upgrade your stash, so you can claim more than 1 scrap per claim. However, if you don't raise your defense at all, it may make you a bit of a target, although I'm pretty sure Gnome added a 24 hour immunity feature for new players, so you can hold off on that.
Also the quickest way to get scrap is to steal it during a battle with other players, so in order to participate in that, you'll need to increase your damage by at least 1 stage! I think you need both attack and defense honestly
Attacking is how you actually make enough scrap to do anything
But if you have a weak defense you'll never be able to stockpile.