Poly Lock, its a little pricey but worth it. I had a 36x18 and almost 700sq ft of 6mil didnt move on millimeter all summer. I had some wind protection from trees as well.
To anchor the greenhouse get some 2 hole emt straps.... get a hammer drill .... get some concrete anchors ..... anchor it to the slab. For the plastic hopefully its long enough to overlap on sides and roll up some 10ft timbers in it to hold it down
Shoot .22s through some 2x4 into the concrete. Lock down the pipe with fasteners to that block. Drill another 2x4 on top of that 2x4 in a perpendicular fashion. Then secure the plastic to that perpendicular 2x4 by sandwiching it between another 2x4. "Cinch it" and anchor it with a hammer drill and concrete anchors. I use the one that uses a .22 caliber cartridge.
Shits still gonna rip in 50 mph youre going to need a windbreak or a footing.