thick leather strip is the old fashion way to reinforce that
and if not done it will tear even with grommets
you can use heavy canvas or plastic or wood or metal
may not need the grommets but they can hold the layers together
if sewing a sailors palm and curved needles help
normal thimble and strait needles will work
as does a perfing wheel
https://www.google.com/search?client=firefox-b-1-d&q=perfing+wheel
to get even strait stitches
glue or rivets will work also