Just googled the club you are going to and it’s under the Gracie barra camp. Same as me, good choice 😉 To begin with I would imagine that they will teach you the fundamentals as in breakfalls, rolls, “shrimping” and some basic self defence. Also they will show you some of the basic ” finishing” moves as in armbar, kimora, omaplatta and rear naked choke. If it’s like the place I go to beginners are not allowed to roll until they reach a certain standard ( for us it’s not untill you get a couple of strips on your white belt.)As for advice, just go in there and enjoy it. I used to think I was pretty fit from all the mtbing, gym work and doing 4 years of traditional jappanese jui jitsu but bjj is an whole new world.