WoW Raiding and Dungeon

I have a few question regarding raids in WoW. I just downloaded the trial version. and getting BFA in October(bcz of exams).

1.How do i find people for raids? Is there a lfg website or ingame tool or is it matchmaking.

2. If there is lfg what are the chances i will be accepted into a raid group considering i am pretty experinced with my class and have knowledge of the raid mechanics at that time. Will people ask for completions or anything like that?

3. Whats the differnce between Raid and Dungeon?

I know some question might sound stupid but Ive really liked WoW and really want to invest time in it.

Since you plan on playing on official servers, you should try official forums.

I didn’t play retail past WOTLK, but I know they have lfg tool for raids. It is automatic and you need to meet gear requirements. Harder content requires manual group organization.

Gl hf