I have a DC who started a school leaver apprenticeship immediately after A level results last summer at a location five hours away. Opportunities like this can be amazing but are not for the faint hearted. It is not at all 'like going to uni' and your DS needs to be prepared to build up a social network from scratch without a lot of structured support.
For your DS to make an informed choice, he and you need to get lots of information, fast.
Go onto Moneysavingexpert and use the income and NI tax calculator to get an idea of what his gross pay translates into monthly net pay. This is your budgeting start point.
Your DC should contact the HR team who issued his offer to say he would like to clarify what practical support is available in relation to accommodation; this is unlikely to be monetary but they will understand why he is asking the question and will most likely put him in touch with his intended team leader and existing apprentices who may have already dealt with the same issue at the same location. There may an existing employee who can help with regards accommodation, have contacts or at least advise on locations to consider and other practical points.
Your DC (with your help) needs to start getting an online feel for what property is available at what price (room in family home, room in shared rental etc).
Private halls may be available but only if the location is a university city or town and may not be ideal if he needs to be at his desk at 8am every weekday and fellow residents do not.
A point to note is that apprentices earning over £195pw are usually liable to council tax so you may need to factor that into budgeting, depending on what is or is not included in any rental arrangement.
Apprentices get time off for study (sometimes one day a week; sometimes block release) and whilst some of this may involve physical attendance at a university, lots of study will be in their home so they may well need space for a desk in their rented bedroom (ie not in shared communal space).
It all might sound a bit daunting but pulling together the information flagged above will help your DS get a sense of whether it will all work from a practical perspective and whether this is something they really want to do.