Hey, im pretty sure you are looking for the layout guide feature. Its placed in the right side panel when you click on a frame.
 

You could also set them up as a style in the right side panel. (Click on a blank space in the canvas, if you cant see the file options) After the style is created you can apply it via the icon left to the “+” seen in the screenshot above.
 

With shift + G you can toggle the guides on and off.

Thanks so much but I am not seeing exactly that.

I have no problem figuring out how to make a grid, but when I do play around with that it keeps changing the size of the frame.
This is what I am seeing.

UPDATE: I have started again with a new frame and I have had no issues.
Hmmmm. Any idea what is wrong with the frame below?

Thanks for your time and consideration. 

Ah I see, dont get confused with “Layout” and “Layout guide”. These are two seperate menus with different purposes. You might need to scroll down, to see them both at the same time.

1. The layout menu is for your overall frame size and auto layout functions.
2. Layout Guides are purely visual grids, columns or rows that do not interfere with elements inside your frames. (similar to rulers from traditional graphic programs)

Thanks that is helpful.
Do you know where I can find out more about auto layout functions?

Hey, glad that I could help! The Figma Playground File about auto layouts should be great starting point to learn everything you need to know: https://www.figma.com/community/file/784448220678228461