@Adeline95 I second the suggestion not to use Instant Book until you have a bit of hosting under your belt. Same for long-term reservations. Limit reservations to 2 weeks max or less at this point.
Spend some time reading through all the host-related information on the Help section of the Airbnb site- your question about when do you get paid is quite basic and that info , as well as more, can be found there.
Navigate around your hosting pages, clicking on everything to find out how to access various info and settings specific to your listing. There are things buried where they are hard to find- the site isn't that intuitive or user-friendly.
Also spend some time each day reading through posts on these community forums. It's a wealth of information that you'll find valuable.
There's so many aspects to hosting and dealing with Airbnb, that it's hard to give all the advice a new host would want without specific questions.
Happy hosting!