Deductions & credits

I sell 10-20 personal items a year on ebay  and end up getting a few thousand from it. I buy the items new and have the receipts. I'm in a state that says over $600 needs to be reported.

 

If i bought a iPad Pro two years ago new for $1200 and sold it on ebay in 2020 for $600 can you claim that as a loss? Most all of the items i sell are that way.

 

The 1099-k from paypal includes shipping, sales tax as income how do i deducted that? There are also seller fees, paypal fees.

 

I do work for a employer 9-5 if that matters. 

 

Thanks