Ukulele to tenor banjo - chords??

Ok, so I have minimal knowledge of music theory, but I really want to learn and while the information on this site is extraordinarily helpful, something is not clicking!

I have memorized most of the common chord positions in GCEA tuning, but I don't know how to transfer that knowledge to the DGBE (chicago) tuning of the tenor banjo. I mean, I can see on my chord chart that the position that would be an F on the ukulele is a C on the tenor banjo, but is there an easier way (besides re-memorizing chord names with the danger of mass confusion in the future) for me quickly figure that out when I am playing?

I am going to my first St. Louis Banjo Club meeting tonight with a borrowed Tenor Banjo, and I want to be able to play the songs in the same key as everybody else!!

Any tips? or is there no short cut?

Also, can I use the same chord positions with other banjo tunings? - does changing the tuning just change the key?

Baritone ukes use DGBE tuning. Find some Bari chord charts, and you should be ready to go.

I ended up using guitar/chicago tuning on the banjo and capo-ing the 5th fret so that I could use my ukulele chord positions and keep up with the banjo group! It worked out fairly well, but I suppose I'll just have to memorize the new names for the chord positions...

I would suggest learning the shapes without names.
Learn which finger is the root note of the chord and you should be good to go.
You have already figured out that GCEA is DGBE capoed at the fifth, so you are far ahead of most.
I came from guitar and used to go through the same gyrations trying to play GCEA. Today a year later I don't even think about what chord I am playing.
Put trust in your fingers and ears, they will guide through the musical maze.

That's what I was looking for! It sounds so simple, but I just have trouble wrapping my mind around music theory. I have started to learn 'what makes a chord a chord' and how to find the same chord with different positions on the uke, but I guess it would be helpful to learn the fretboard, and then I suppose if I learn the DGBE fretboard, I'll be able to use the knowledge of chordroots and finger positions to find the chord I want? I guess I have something to work towards!

You'll have to write them next to the chord that you are used to playing-C is G, D is G, get your charts side by side and write them out there. I have to think it the other way and transpose into uke/ or 5th fret chords.
I think it from the bass fret board-a 5th above or below but that might complicate things for you. I was playing uke last night at the Newport Beach pier with some guys on guitar, I can transpose fairly fast except when we played in E- the minor caught me every time.

Not sure if you are interested in doing this, but if your tenor is a short one, 31" or so, they are regularly tuned to GCEA in the same way some baritone ukes are. Some call them baritone ukuleles. I think some tenors are a little too long for this tuning. I have been looking at several 17 fret Irish tenor models