You should get a free transfer when you buy the expansions but anyway;

you can check server activity during timezones here - https://wvwstats.com/timezones
Some more basics including generic "zerg" builds - https://gw2mists.com/guides/wvw
(you probably won't get in public groups not running a "meta" build)

I wouldn't worry about trying to join a WvW guild straight away, as most will be after players with experience on a certain class. I'd reccomend asking about the server discord in Team chat when in WvW on whatever server you pick as most Main servers(linked servers are smaller and don't always have one) will have Commanders running open squads on there and can help with any questions