You will learn as you go. I was very nervous when I first joined a guild and thought that they might kick me if I do not know what I am doing. Good thing our guild leader Troy was very understanding. In fact, almost all of us we're first timers. LOL.
Depending on the guild leaders, they might require their members to contribute DEC and some cards. In my current guild, we are required to contribute 250 DEC per season to upgrade our buildings.
We currently have 5 sub-guilds in THGaming, from serious brawlers to people just want a guild to chill out. We have very understanding guild leaders too. 😊 If you're interested we can try finding a spot for you.