Accommodation type varies from university to university. Choosing accommodation should definitely be part of your university research. You need to consider if you want ensuite facilities, catered facilitates and indeed what you can afford, as well as the location. All universities have teams of people who specifically advise students on accommodation. Please contact the university directly for more help.
Once you’ve replied to your decisions on UCAS TRACK, your universities will start getting back to you about accommodation. If you’ve got an insurance choice, the first thing to do would be to check whether you need to be applying for accommodation there too. Some universities will allow you to, but others won’t let insurance students apply until after A Level results day.
The vast majority of universities will get you to apply for accommodation around March/April time, and then allocate it soon after results day. Please check the individual university websites for specific accommodation information and application deadlines.