I'm sure some of you lower levels just starting out or have been around for a little while are having trouble just getting metal or oil for upgrades so here's some easy ways to make life of a low level nice and.
First if you're just starting out, there's no lying it can be ruff but after the tutorial you need to destroy low level rogue bases (level 5) these will give you resources and special ops. You can use the ops to get more resources and use the resources for upgrades. you'll mainly want to focus on unlocking new tanks upgrading storage and riflemen. One major thing the special ops can be used for especially at you level is destroying other players bases. Destroy at-least 5 bases a week and you earn medals, the more medals you can get the better. once you get enough and unlocked the right units you should buy the hover tank and then the surface missile; once you do this you'll be set
PS this is what i recommend when starting out not stating you have to do this in any way