If you like Xot, anything Numenera could work. I tend to roll my own, so I haven't read much of them though. 😅
If you like Zone, just literally run S.T.A.L.K.E.R: Clear Sky the video game. 😛

My tip, whether you run modules or not, is to focus your prep. I use Sly Flourish's 8 steps, that he's since put into CC so you can just get it here: https://slyflourish.com/lazy_gm_resource_document.html

He mostly runs 5e-type games, but I've used the same steps for Forged in the Dark games, 24XX and others. It's just a way to make sure you have things you can prep, and so you can feel confident when you later improvise at the table. Sometimes I change or rename the steps to better fit what I'm running.
I'm using them now while running the Saltmarsh campaign from 1980-something.

Don't underestimate the value of a bullet-point list.

If you want maps, here's a thousand of them: https://dysonlogos.blog/maps/
There's also generators, I like https://watabou.github.io/.

But, above all, keep it simple... If in doubt, grab a watabou region map, roll on the Xot tables to see what the town of Blackfire or whatever is about, and what they need, and have an NPC ask the PCs really nicely to pleeeeeaaase do the thing. They're the only ones who can. Pick a random Dyson map for where the thing has to be done, and just go with it.
It doesn't have to be Lord of the Rings to be fun. (actually having just come out of GMing a LotR campaign, it shouldn't be...)

PS: Sly Flourish/Mike Shea also films his prep sessions, and they're about an hour every week: Here.