HI Jake,
Welcome to Coda! Yes, it is slightly different to Excel, but once you get the hang of it, you will never look back.
The formula in Coda is Max().
In the example below, I give formulas both for the Max for the whole column, and how to get the max for a group of entries in a column.
The screenshot is from my Formula Reference Manual below. (Still a work in progress… but cover about 40 formulas so far.)
Regards
Rambling Pete