No student union or university is arranging club nights/balls etc for freshers. The only tickets on sale are from dodgy promoters hoping to scam naive freshers out of their money.
Freshers week will happen in that freshers will have a first few weeks getting to know their new city, halls, coursemates, campus, clubs, societies, sports etc. There will be introductory sessions to your course and lots of opportunities to make new friends. Freshers is and always has been about more than tacky glowstick themed club nights.