Gooday everyone!! please i need guidance on applying to study masters in the UK

currently i live and work in Dubai, and i want to go to the UK to study my master degree. the course is APPLIED AI & DATA SCIENCE and the school I'm considering is SOLENT UNIVERSITY in Southampton. this is my first time of undergoing this process and I don't wanna use agent because nowadays some of these agents are scammers and fraudsters and I don't wanna be a victim to their scheme. please I need answers to some of the questions I will provide below.

1. Is it compulsory that Nigerians must write IELTS or does Nigerians need a result such as WAEC to show proficiency in English?
2. since I will be applying from Dubai, which documents do I need from Nigeria apart from my transcript?
3. are there any schools anybody can recommend for me that is not too expensive and has a nice environment.
4. during my course of studies I wanna work to pay the remainder of my tuition fees and I wish to go to a place where I can find lots of par-time jobs, please I need recommendations.
5. After completing my masters program, how long will I stay in the country and is it still possible to get residence in the UK?
6. can someone explain more about CAS?

Please I need answers to these question and I will really appreciate it.. thanks and God bless you all

hello, please i just wanted to know if university of regina is approved by government to is issue PGWP?