Library - it will be doing the summer reading challenge and maybe some craft activities
Local museums often do summer hols stuff
I used to scour websites and pick up leaflets to do anything
Have one thing a day - swimming, park, bus into town, museum, board games at home, friend to play, nature walk with list of things to find, cookie baking, water fight, soft play, den building, bike ride.
Then something calm for the rest of each day - movie, craft, reading, Lego, holiday diary.
Any friends can give you a lift to further places?
ETA loads of great ideas here @Colbie34
Second church holiday clubs, usually free or small donation; also supermarket cafes