Branching out...

[Rizzi]

I've been role playing one on one for years. However, I do not have much experience in group roleplays. Though lately they have been catching my attention. Therefore, I am wondering if there is a sweet soul out there who could tell me how group roleplaying works or would be willing to take me under their wing and show me how it works.

[Halo]

It's not much different to a 1x1, really. The main difference is the existence of a GM.
As a player, all you do is make your Character Sheet (a description of your character, the base-version of which should be in the OOC), wait to see if your character is accepted, and then participate and post in the IC. There are rules around this (e.g. no making yourself super powerful, restrictions/requirements on posting frequency, sometimes there are posting orders, i.e. the order the players post in is dictated), but they should be explained in the OOC. I'd recommend starting with this, and gathering an idea of the GM's role through playing - that's what I did!
The GM is the one who creates the roleplay, decides which characters are accepted in, etc. They're also the ones who direct the roleplay's narrative through their posts a lot of the time. They have ultimate control, particularly over major events that drive the roleplay. They're very much like a Dungeon Master in Dungeons and Dragons, if you've ever played that,

[Foster]

Usually there's an informal posting-order that may or may not have much slack allowing tiny 1x1 convoes to occur.
-Lack of this result in 'rabbit-posting' because it looks like the posts are mating like rabbits.

There's also players that are not directly interacting with your character, but when they come into contact, are going to need to bring you up to speed/brought to speed on what either respective sub-group was doing.
-This may even abuse 'fluid time' since posts can take-place in flashbacks and time-skips independent of other groups, so getting things to mesh again can be tricky. For extremely-divergent sub-groups it may be necessary to create separate threads within the same continuity.

And lastly, it is possible to go AFK, and hand the controls for a character to the group in 'auto-follow' where the character is present, but just not doing anything outwardly worth mentioning (alternately, are directly controlled by someone else as an NPC).