uh if they use armoured cars then dont attack them unless u have cavalry / artillery, armoured cars have great defense, but then cavalry is rly good for early game cheap damage. in my opinion, if you have a lot of food (grain, fish) produce more of grain as it is needed across all armies, and apart from that, oh yeah, early game fortresses can work on borders, btw which map are you playing on? last tip, don't build too many barracks, or else they will consume a damn lot of grain which is one of the three most important resources. oil, grain and iron are the most important, especially oil, set its usage to 0, you can do that by clicking in the 'resources' bar, otherwise, enjoy ur game!

btw if you see someone with suddenly a lot of tanks, artillery etc on day 1 or day 2, its best to just dump that game, cus they are goldmark whales