Ukulele
This is not a quick project, but it might be fun as a family activity. You will need access to materials and equipment but I believe you might be able to come up with alternatives ... be creative!
Bagpipes
PLEASE check with your parents before trying this one!
Playing a recorder-bagpipe is a lot harder than it looks.
Under Construction
Here is a video with some ideas for creating simple instruments
This is a site with ideas for making your own simple instruments.
https://www.learningliftoff.com/make-homemade-music-with-these-6-diy-instruments/?fbclid=IwAR12OtHwkK09ufG-Z96lfJMPv-y9KR9JY4_mXwxHQfyQ5zZjLz_m_8JxrMQAnd another site full of ideas.
https://feltmagnet.com/crafts/Music-Instruments-for-Kids-to-Make