See pic related
I know how to measure it I understand that much
but I have no clue what the symbol or the numbers mean. Do tell.

Thanks

Float height adjustment is 26.0mm plus or minus 1.0mm either way is ok. The other numbers are measurements in inches if you choose to use that measurement. 

The picture is not related to the float but is showing you the needle adjustment position when you adjust it if needed. 

Yeah I thought I cropped it to just show float adjustment
thank you!

Float arms should be pretty much parallel to float bowl gasket surface. In fact, I usually just set them parallel to gasket surface.

(Sometimes Yamaha specs are wrong... and in early years they measured from a different place... so if arms are not pretty close to parallel with gasket surface just as valve closes, something isn't right)