How do I use VLOOKUP or XLOOKUP functions in Excel to track billables?

I’m trying to keep better track of my billables for my business for the upcoming academic year, but I’m not proficient with spreadsheets. I’ve screenshot my workbook and attached what I wanted my end result to be.

Based on everything I’ve been researching, it looks like I’ll be using any combination of the VLOOKUP and XLOOKUP functions to render my final results.

Any help/walkthroughs are greatly appreciated.

Thanks!