Here, I'll try to explain.
In all roleplays, you make a character.
The most common role play (I think) is the book roleplay. You fill out a form for your character, including looks, personality, etc.
Then, you use that character, and pretend it's real. If it's an event type, each new part will have a scenario. I'll take "Playing Celebrity" as an example. In the first part, it had a scene which was in a club, and the main objective was to just socialize. There, you use your character to talk, meet, etc. other characters. The next was set in a concert, so your character would be at a concert and it would go on from there.
Ex:
Alina sat on a stool near the bar, her gaze flickering across the room. She was a bit shy, and this whole Hollywood scene was new for her.
Then there are others which are like place roleplays. Most of these are stuff like towns, camps, schools, etc. I'll use Ash's roleplay Ballards. Ballards is a boarding school roleplay. She just uploaded all the stuff on campus like Dorms, Nurse, Starbucks, Classes, etc. So there aren't any events, and you just talk through characters at places. If you're confused, just tell me. I'll try to help more!