I want to pull a report that brings in Customer, Invoice, and Sales Order but having a hard time finding the fields

You will need to start with a Transaction Saved Search. In the Criteria select the "type" field and choose Sales Order & Invoice (This will filter only these transaction types) I would select the field "Main Line" as true unless you want to show line detail

this is a great start. Right now it is returning multiple accounts and sales tax. Should I just filter that down to reduce the data?

The Main Line line should resolve that. Set Main Line to "Yes" This shows only the "Top Line" view of the transaction. You can alternatively filter out non-relevant accounts, but ideally only if you are wanting to isolate a specific account

you guys are great. that helped. is there an easy way to relate invoice back to sales order with this search? or should I just do that in Excel?

Yes. On the invoice there is a field called "Created From" This field references the Sales Order Number that the Invoice originates from. If it is blank, the invoice was created as a stand alone invoice. You might want to filter this down a bit to only show the Sales Orders not yet invoiced and NOT show the Sales Orders that have been invoiced, but show their respective invoice. To do this you can add a criteria to the field "Status". And show all Invoice Statuses, but only Sales Orders Pending Approval, Pending Fulfillment, Pending Billing, & Partially fulfilled. This would help prevent duplication of transaction $$

Do I have to create the saved search first and then filter? I don't find those options on the Transaction Search page

Yes, you will have to create a saved search to open up all of the available options. It is not required for you to actually "Save" the search if you are just validating data at this time

trying to figure out how to pull in the "Created From" field. I can add it on Advanced Search but have to have a value in there

Create a saved search. Then in the results tab add the field "Created From" as a column. It will either be populated or blank

you can also look in to applying transaction or applied to transaction fields