What file enforcement should be set on file upload for best user experience?

We make website and we want our users to do things as they are supposed to. But it's not like everyone knows everythings...

I'm creating a website ashiane.house that suppose to allow user to share their property information with other, in term of Selling, Renting, etc...

As we all knows these kind of websites, do not have a specific operator, and all kinds of user work with them, from professionals to people who may only use the computer for only necessity.

So is it good to enforce Specific image type? what type of image other than JPEG should we allow? what's the minimum file size that we should allow our users? do typical users knows how to decrease image size?