I just arrived UK to study in the past month, so I'm basically a newbie, yeah I have some knowledge about the visa application process, but mine was pretty straight forward, so if your circumstances are outliers I can't help. I'm navigating the terrain all on my own and reading other threads to get as much information as I can (for myself) since I'm not big on asking questions. I hope others are in my situation find this thread and we can help each other out.

For those about to arrive or have just arrived, of course you must have booked for your post arrival test day 2 and day 8 and have a place you will isolate for 10 days. Please note it has to be 10 days, even if your day 8 test comes out negative, and for the next 4 days up tp day 14 you should still be careful, its normally supposed to be 14 days but they don't want to keep people locked up for 2 weeks. If you are staying in England, there is a test to release scheme, where you buy a private test in addition to you 2 compulsory travel tests, you can take this private test on day 5 and if it comes out negative and your day 2 test is also negative you can end your isolation after 5 days. You must book the test before you travel and fill it in your passenger locator form. its only for people staying in England, price is from 20 pounds to like 100 depending on the test provider or if its a home test or on site.

Once you are done with isolation, you should try to find a long term accommodation if you don't have one already. There are many websites that can help with this depending on your location, there are also private student accommodations. Your budget, transportation costs to your school and proximity to everyday life are things you should consider when choosing an accommodation, there are also flat shares. There is one for every price range, some require deposits, others do not.
In relation to accommodation, students do not need to pay council tax, To count as a full-time student, your course must:
last at least 1 year; involve at least 21 hours study per week. There are some exemptions ( you can look that up) but all you need to do is get a tax exemption letter or a letter confirming you are a student from your school and email it to your council (this might vary depending on your location). If you are staying in private accommodation with non-students they might give you a discount or you might not pay depending on the landlord.

Important things you need to do as a student after your isolation is to collect your Biometric Residence Permit(BRP), where to collect this will be in your Visa support letter (UKVI document). Secondly, you register with a General Practitioner(GP), incase of any medical emergencies, your school will have recommended GP(s) you should register with depending on your accommodation. A dentist and optometrist might be useful but your health surcharge doesn't cover these.
You will need a letter from your school to open a student bank account, your school will have a list of bank branches that accept this letter, they'll be branches generally in proximity of the school. Get as much information as you can before you choose a bank.

Explore your city or at least your postcode, you need to know where everything you'll need is. Supermarket for groceries, restaurants, electronics shop..... you should know the shortest distance to your school if you are walking or the cheapest if its public transportation. Taxis are generally expensive, so your best bet is buses or trains.
Very important, no city in the world is free of crime, thankfully everything here is recorded, most cities are generally safe, but there are places you shouldn't be at night, find out where these are and steer clear. Please always be mindful in large crowds, there are pick pocketers, the last thing you want to lose is an important document you can't get back. Never carry large sums around, I think for the me, a large sum is anything over 50 pounds.

This is where I have gotten I hope this helps, and please if any f my information is misunderstood or incorrect, let me know, I definitely don't know everything and just learning everyday. I want to talk next about National insurance number for that want to work and COVID vaccines for those that ae interested in taking it. Thanks for reading.