I've been going to the spring show regularly, never been to the fall show. I'd made it 4 years in a row (it's about a 4 hour drive for me) before COVID canceled last year's.
I'm intentionally avoiding this year. Currently, prices everywhere are insane and my experience with "normal" times at Wanenmacher's there's plenty of over priced stuff that folks aren't willing to haggle on.
If you've never been there, I don't think you can really grasp how huge it is. If you're going to browse, and stop to look at everything that catches your eye, you won't be able to see every booth in a day. If you have a list of specific things you want, keep your head on a swivel, and are good at playing Where's Waldo, you can hustle through all the isles and people in a day. Wear comfortable shoes, maybe take a back pack to haul your loot.
In '19 I took some friends with me, they were first-timers, they wanted to stop and look at every neat thing. I abandoned them early, they were slowing me down. I had a list of about 8 things I was looking for and came home with 2 of them.
Similar to the OP, I'm a Marlin fanboy too. It's hard to know what you'll find, in '19 I had a Camp 9 and a early rifle length, full length mag tube, Marlin 60 on my list. I came home with a Camp 9 and a 6081 Alamo. In '18 I scored a .357 1894 at Wanenmacher's, that it took me 3 years of searching gun shows, Armslist, and Gunbroker, to find one I was willing to pay for. There's still a lot of stuff on my list I don't have, there are some truly delusional sellers out there, especially at Wanenmacher, it's easy to get disillusioned.
My first trip there, I went with my uncle and a friend of his, they're both high roller, petroleum industry pensioners. We were after a grade III or better, .308, Belgian, BAR. Apparently they didn't make a lot of .308 BARs. That was our focus, the whole show, we found 2x .308 BARs, a grade II and a grade IV. We came home with the grade IV, so if there's something rare you're after, and you're willing to pay for it, you'll probably find it.
It's literally 10+ acres of guns and accessories, don't expect to do it all in a day, expect to be annoyed by the crowd and prices, wear comfortable shoes/clothes, there will be a line at the bathroom so plan accordingly.
I didn't think it was possible to get tired of looking at guns until I went to Wanenmacher's.