So I was thinking of running SSP COOP. First off do the other players I going to play with do they have an account on speedrunning.com? Also how much do they have to help? Can they just be in the world or do they have to come to the end with me? Can I go the the portal 200,000 blocks away from spawn and they are at the spawn point or do they have to come with me? And do they have to be in the world the hole time? Can they join half way through or leave before I finish? Thanks for your thoughts everyone.

They don’t have to have an account, and they don’t have to come with you during the run. The cannot join or leave the world mid run

Any player can leave and join the world at any moment of the run And It's better if they help you ... But as long as the final goal is completed should be fine. Altough it's always preferable that everyone is doing something actually useful for the run