Yeah in Battlegrounds the rounds last a while but if you die you can just exit to lobby and queue for a new round.
As has been said to stop camping a safe circle appears on the map after a while and if you’re not inside it when it activates you take damage (initially not much and the circle is huge but the circle contracts every few minutes and the damage taken being outside it increases). Part of the strategy is guesstimating the final circle position and getting there in time so you aren’t killed running across open ground by people camping already in the circle (but also having enough gear before you move that you have a chance of winning).
Good aim helps a lot as does knowing the various weapons + map knowledge but IME they’re less of a big deal than in straight FPSs like CS (where a lot of people seem to have pixel perfect instant aim + know the maps inside out).
Worth watching people like Lirik or Summit1G on Twitch to get an idea of the game before buying it (they make it look easier than it is though :p )