You can honestly start with RB immediately.
Some nations are pretty hard to play in AB due to the automatic spotting and the like, others perform a little better. RB will make your heavier tanks feel way more sluggish though, so do beware.
Big thing with RB is to pay attention to how and when and who moves where. This will help lower the amount of times you get killed by people you did not see. It will also help you get some cheap kills by catching enemies moving between covers or getting behind them safely.
This is a decent tutorial series. Don’t binge it or pre-watch, but worth checking if you struggle with a specific map. Unfortunately, with the frequency of map changes some of it may be outdated but the gist should still USUALLY apply. https://www.youtube.com/watch?v=Fl696b3ogNQ&list=PLBNhloJF1XMSFlEGJ_5tS0reFPeTMKbAx&index=1