Hi there!
I can't answer your question regarding commuting but hopefully someone else on here can! But I will share my thoughts and opinions on the rest 😁
The iPad or laptop question is more of a matter of personal preference, however, I would say that a laptop is more of a must-have for me. I've got both a MacBook and an iPad, and I made it through my first year with just an iPad. However, I found personally that I needed a good laptop since I found that I was quicker at typing notes than I was at writing notes using an Apple pencil on my iPad. I still use both an iPad and my MacBook and they both have their individual uses, but it matters more about how you would use them and how you prefer to study.
A backpack is a must for me! I also take a shoulder bag or a tote bag to university sometimes, especially if I'm only planning on using my iPad which is easier to carry in a smaller bag than a laptop but a backpack is more essential I think. I would say that a backpack is a necessity as it can carry everything you need, and if you invest in a good backpack, you will be able to keep it for your later years when you're more likely to be carrying more things like print outs, folders, and textbooks. If I've got a full day on campus, rather than just a lecture, I will be carrying my laptop (and maybe iPad too), my chargers, notebook, pencil case, snacks, water bottle, emergency kit (plasters, medication, etc), and sometimes lunch. This is able to fit in my backpack well and since it sits on both of my shoulders, it doesn't hurt to carry like it would with a shoulder bag.
And finally, my essentials include a good water bottle, a good routine, and a planner/way of keeping track of your studies. The water bottle is 100% needed as it saves you from spending money on drinks every day, and usually, when you're studying you can find a water dispenser nearby, preventing you from having to leave the library or wherever you are just to hydrate. I've found that a good routine that works for you, whether strict or quite lapse, is needed to keep on track and keep you going. This could include when you wake up, eat, or go to sleep, how you study, or how you take your notes. By keeping with some sort of routine, I found that it helps you stay motivated and invested in your studies and your personal life without getting lost. Finally, whether it's using your notes app, a notebook, or a formal planner, by having somewhere where you note down what your assignments are, when your assignments are due, when your exams are, etc, you can make sure you don't fall behind. You can also avoid any accidental late entries and make sure that you're not leaving things to the last minute. This also helps with preventing you from worrying about your studies, giving you more time to spend doing things you enjoy and socialising!
Hope this helps!
Jen (UoS student rep)