Most of the time you can play it in chunks, there's always something to do for just 20 minutes if that's all you have. However, even if you were very efficient and used a guide to find everything, you'd be looking at a 50 to 100 hour game for a relative newcomer to the series, so if you only have 3 or 4 hours a week to play, its worth asking yourself if you really think you'll stick with it for that long.
If you do want to go for it, id suggest watching a few of Fextralife's
beginner builds on Youtube to see if there's anything that sounds like your thing, then check
their wiki to find the items you need for that build.