I definitely don't think it's too late to join a society in January!
A lot of universities have something called 'refreshers' in January and they have fairs which you can go to and look at the different societies on offer. If yours has this it may be worth going along and talking to the people running the societies you are interested in. They may have free trial sessions as well where you can try it out and see if you enjoy it. A lot of new people will join around January time so you won't be the only new person don't worry. The social aspect of societies means you won't be left out as there will be lots of activities which involve everyone so there will be lots of opportunities to make friends with everyone, even if they know each other already.
It's definitely worth a try, you may love it! And if it's not for you, you can always rejoin next year but you may as well try now if it's something you are interested in.
Lucy- SHU student ambassador