I forgot to add some stores that might carry these.
I go to Micheal’s since it is the only decent store around here. they carry most of the Winsor and Newton brand and a good supply of Krylon sprays. It also should carry most craft paints in every color you could want.
Jo-Annes is less diverse, it usually only has craft paints.
Most acrylic mediums(retarder, fluid improver,Gel) you might need to go online. I only use Dickblick.com since as far as I have seen they have the best prices and the most diverse selection.
If any one else knows other other stores that you go to get your supplies, feel free to list them.