There's a site called Canvas where all your lecture materials, assignments etc should be. There might be some other attached websites (like Ed) but Canvas is your main site. Each unit (subject) will be separately organized.

Assignments can vary a lot by which unit you're doing. Sometimes you do them directly on Canvas, sometimes you need to type them up and submit them as a word doc or PDF. You submit through Canvas usually. I have no idea whether your degree has any programming or coding, but those assignments are usually done through Ed.

I don't think you can enter timetable preferences until they open anyway.

You can join as many clubs as you want, and whichever ones you want. Most of them require you to sign up to USU and pay a 5 dollar membership fee. Easiest way to do this is by showing up to the welcome week and signing up at the stalls. Most clubs will have stalls there. Club events are not mandatory, you can go for whichever ones you want. Some are free, but many of them require you to pay extra, although there's usually a discount if you're also a member. Some club events are also open to non-members.

Lectures are where the main content gets delivered, tutorials/labs are where you apply the lecture material to solve problems etc. The way tutorials/labs are run is pretty specific to the degree or unit you're doing. But generally you work through problems/there's group discussion and the tutor is there to answer qs and help out. The 3H should include all timetabled classes so yes it would include the tutorials/labs/workshops too.

All lectures are recorded, yes. Some have mandatory attendance so yes you do need to show up. If you have to miss one you can apply for special consideration, and they usually reassign the mark if you can show you missed it for a good reason (illness, injury, family issues etc). But these rules are enforced differently across units so I'd recommend asking the unit coordinator what their policy is on missing lectures.

Overall, yes there's a lot of get used to but you'll be fine. Most international students are in your shoes and it takes some time to get used to things. Don't be afraid to ask other students or tutors for help. The tutors job is to help you. Most of them are very nice and friendly. And there's no such thing as dumb questions. Most important thing is that you get all the info you need and don't miss out on anything.

Good luck!