Basic premis: try to do 30 min exercise every day in June.
Any kind of exercise: walking, running, swimming, climbing, dancing, circuits - the choice is yours!
From experience, every day can be a bit much. So feel free to join in even if you don't think you can manage this. Last year I aimed for 5 days per week, which worked well for me.
If you want to start before June, there is a thread here