Most volunteers find they gain more than they give.
You will have a far better chance of finding the right opportunity for you. The staff at the Volunteer Centres will try to help you clarify your needs. They will never try to persuade you to undertake something you do not want to do. Only you can choose what you want. If you only have limited time available, don't be too concerned, an opportunity is waiting for you to negotiate a suitable arrangement before you begin your new career in volunteering.