There’s a few ways of doing it.
1 – Run each of those on the same site. This will need a bit of pre-work to check that all of the plugins that you’re using are compatible, but you don’t need separate sites for each section unless you really want to run them all seperatly.
2 – Set up a Network site. This wll let you have separate sites for each section but still have them all running on the one platform with the one admin area.
3 – Run separate WordPress sites in folders. This keeps everything separate, but means that you have to do admin on multiple sites instead of just one.