Cross Referencing Data Across Sheets

I've read several threads on this and tried to figure out solutions but am still stumped. I am creating a workspace for managing events. I have vendor lists with their rates and a planning sheet with the number of staff we need and which activities will be booked, etc. I'm trying to create an expense sheet where I can have a drop down of all our vendors and it would pull in their rate. Or if I put in the event name it will tell me how many staff worked at the event and which activities we book, based on the overview sheet.

Are either of these things possible or am I expecting too much?

PS. I have tried putting our vendor list into google docs and then using data shuffle to refer to it, but I can't make that work so if that is the solution please point me to something that would help me figure out how to do that better.

PPS. I'd love any ideas on automating a budget from existing data in sheets. I can make a report of my income and one of my expenses, but since you can't really add data from different sources into a report or add custom columns I don't see a way to automate a budget from existing data. Would love if anyone has a solution for this.

Thanks