So on lower hazard levels the game can be pretty easy/slow which gives you plenty of opportunity to learn the ins and outs or to get a warmup mission in. However haz 3 always felt like a good sweet spot where it has challenges but even if you haven't played in a week you aren't gonna get toppled. I also wouldn't consider DRG a game that you would ever need to "practice" to play other than maybe haz 5? But being able to play haz 5 is more about proper loadout and just knowing what to do.