If I have to discontinue service for a while what will happen?

If I have to discontinue service for a while what will happen?
I'm a newbie to wordpress and I need time to learn about wordpress and build my site with my freelancer.
Are all plugins and themes compatible with each other in any combination?
Will I still be able to view the white label videos?
I'm learning about multisite and single wordpress at the same time.
How do I know what themes work with what plugins?