Hi @Brendan7
Right now there is no tools to create a functional grid in Figma, but there are way to do it by yourself:
Nested Auto-Layout
You can create a grid of some sort by nesting one auto layout frame inside an another.
The auto layout panel (on the right) will allow you to choose the direction and the spacing between element in this frame. So basically you want you parent frame to specify a direction (for example vertical) and its children to have the opposite direction (so horizontal) then make sure you specified the same gap value for those 2 and you will have a functional grid
Layout grid
You can play with the layout grid option to create your pattern and then simply drag n drop your item inside, make sure you have the snap to pixel grid checked on (settings > snap to pixel grid)
I hope it will help you, in the meantime you can upvote this idea for Figma to work on