… I would like for the part to show the notes and the tabs on each part …

… Is there a way combine the staff and tabs on the same page? …

It is not clear what you mean.

Do you mean

A) The {Guitar clef staff} part on the upper half of the page, and the {TAB staff} part on the lower half of the page, but as two separate layouts?

or

B) A “mini-score” of the two staves, with joint barlines? (one layout, not two separate layouts)

A "mini score".  So, 4 parts. Each part page would have the the staff with notes and rhythms and the tabs.

I think you would start with 8 staves: guitar/TAB repeated 3 more times. Group each “part.” Do your composition in scroll view (that’s just my opinion!) Then, when you create parts, you should get each guitar/TAB on its own page.

N.B. I don’t use parts, so I’m not certain about that. But if that’s not how they work, maybe staff sets?

… A "mini score".  So, 4 parts. Each part page would have the the staff with notes and rhythms and the tabs …

Document menu > Manage Parts…

To expand the dialog box Manage Parts, click the button {Edit Part Definition…}.

In the dialog box Manage Parts you can

- create new parts,

- delete existing parts,

- edit existing parts (= rename the part, add staves, remove staves &c.).

Obviously you need 4 parts.

In each part a {Guitar clef staff} and a {TAB staff} should be added to the part.

To view a generated part:

Document menu > Edit Part > …

While viewing a part you can use the Staff Tool to add a staff group for the part.

In that way you can make the barlines connect the two staves.

In creating a piano/organ duet, I created piano part on top, with treble and bass with pedal line below it.  However somehow, below all that, but attached, are another bass and treble staff.  How to get rid of them?

Welcome to the forum!

Have you viewed the Finale document in Scroll View? - or in Page View? - or both?

With the Staff Tool you can delete unwanted staves.

Have you tried that?