It's important to consider your general health whilst waiting for any kind of treatment: reducing any excessive weight, stopping smoking, reducing alcohol intake and getting generally fitter can be helpful. For further information on these topics, please visit the NHS Live Well website.
You can find advice on common MSK conditions, and simple exercises to try – these exercises are designed to be safe for most patients but if you're worried about trying them, ask to see a First Contact Practitioner (FCP) or GP at your GP practice for their advice. It may be that you prefer other forms of exercise, which is fine. In fact, exercises that you enjoy – whether that's yoga, walking, swimming, or tai-chi – have been found to be just as effective for a range of joint problems.
The NHS Fitness Studio also has some graded exercise programmes you might like to try. The key advice is to start slowly and gradually build up the time and intensity of exercise as you are able/comfortable to. If you experience any severe pain or swelling because of exercising, then it may be sensible to await your appointment for advice.