Most things can be done in the admincp, then you export the product xml if you want to save or distribute it (it's a good idea to keep a backup even if you're not distributing it). Some controls don't show up unless the site is in debug mode (e.g. adding/editing options and option groups). If you haven't been using debug mode you might find this useful:
https://vborg.vbsupport.ru/showthread.php?t=265999 . The article is on ways to turn it on only for yourself or admins, but the "normal" way (which you'd use if you're developing on a test site, which is a good idea) is there too.