Here are the corrected sentences:

1. My friends and I cleaned up the streets in our neighbourhood every summer when we were small.
2. My aunt often donates money to charitable organisations.
3. They started the project with the aim of helping homeless people rebuild their lives and enabling them to return to the community.
4. Our volunteers attracted over 1,000 people to the campaign over the last year.
5. People can sign up online to become a member of our charity organisation.
6. Volunteering provides benefits to both mental and physical health.
7. Doing volunteer work is an opportunity to gain skills and experience.
8. How about donating our old books, toys, and clothes to charity?
9. Did the organisation provide shelter for the children?
10. Do you remember when you first volunteered?