Volunteering is simple. It’s about choosing to give time to help people, the community or society, the environment or animals.
Your volunteering must not be done for a business but can be undertaken for a charity or not-for-profit organisation. Where your volunteering is in support of surplus generating work, for example a charity shop, then some Local Authorities may require a work permit. The charity you are volunteering with should be aware of this and support you as required.
For your volunteering activity you need to choose to give time to do something useful without getting paid (apart from expenses).
You can also volunteer in a team, which might be an easier way to find an activity if you can identify a local need you can help with.