I prolly have 500 gravel scattered all over. Is there a tool or machine for it?
I don't have a lawn sweeper and I don't plan on buying one, because it's expensive and I don't think it would work well. My leaf blower can't blow gravel. My lawn dethatcher doesn't work, it just pushes the gravel on to the top of the soil.
What can I do? Should I try to vacuum it but I prolly would vacuum out alot of the soil too.

 

If you are not willing to buy a lawn sweeper perhaps you could rent one.
If not that a push broom with stiff bristles would move the rocks into piles to be picked up by hand.

You could also offer 10 cents/rock to some kids to pick them up which could be cheaper than renting a lawn sweep.

 

I generally rake up what I can and forget the rest.

 

I was successful with a little plastic 6" Leaf Rake from Walmart . . . . with stiff little tines.

We had done some drainage around our gardens and had 4" tiles laid on a gravel bed about 3' below grade; but there was a lot of crusher run gravel left lying around on areas that we wanted to mow. It wasn't easy; but these little rakes brought the gravel along in manageable batches.

We have other projects planned, and we were careful to store some gravel on a plastic sheet so that it wouldn't re-integrate with the soil underneath; but it sat too long and the plastic deteriorated making it necessary to then rake that area and pick up the same gravel a 2nd time. Always store gravel on a solid concrete or asphalt driveway.

I'm afraid that there is no simple method.