You should have placed anchors in the concrete along the edge for the walls.

They look like a large 'j' shaped piece of rod with threads on the straight portion for nuts.
you drill matching holes in the bottom plate of the wall and use washers ad nuts to fasten down the plate.

Now that you have already poured the foundation without anchors embedded, you will have to use shield style anchors.

Lead shields wood likely not be acceptable since they have poor withdrawal resistance.

Something around 3/8 inch diameter and at least 6 inches long should do the job.
They have spec sheets that give the anticipated shear and withdrawal resistance.

Loads of both types will be present.
the wind will try to push the whole structure sideways, creating a shear load on the fasteners, while it also tries to rotate about the lee side producing an uplift force on the windward side fasteners (the wind tries to tip the structure over, or roll it).