Hey all I'm looking around to see if I can get some advice I'm currently working on a website with a friend (can't go into much detail about it) but simply put I need to know how to go about setting up 3 main things at the moment

Chat rooms
Subscription/membership page
video streaming as well

I know this might be the more complicated stuff since I'm looking at PHP etc but is there any ideas on what code or programs I would need to set these up?

currently the website is set up on RVsitebuilder we're pretty much adding our things through the HTML via copy and paste since the builder doesn't allow importing webpages 

Any help with this would be greatly appreciated