I think gopher would be better, just by how much content is available on it and how stupid simple it is. But either option would be really flipping cool to see!
Gemini actually has more domains than Gopher these days, from the statistics I've seen. Maybe not more content, due to Gopher's history, it's hard to say.
So starting there will let you branch off to whatever you find interesting!
If you dig enough, there's content you won't find anywhere on the modern web too, especially from really old sites that are still being hosted from back in the heyday. The further you go, the more old stuff you'll find.
It feels like exploring ancient ruins that have been long abandoned.
What's unique about Gopher (at least to me,) is it goes a bit beyond just hosting content like how we see the modern web. There's a lot of history and culture around it.
The protocol itself is extremely interesting to dig into. It's simple enough you can use telnet or curl to browse (clunkily of course), but there were many attempts to extend it in crazy ways. For example:
How it started and became popular is very cool to look into as well.
Currently, the main content creators on gopher share a deep "counter-culture" attitude towards the modern web. You'll almost never find an ad, or junky blog posts that are nothing but fluff. No popups, no politics (like the EU banner thing), or even seeing a webpage being rendered as it loads.
It's all so simple the only thing you can host is pure content and links. And users/content creators take a lot of pride in that fact.
Anyways, apologies for the ramble. It's just a big passion of mine. Good luck on your first dive :)
"Malicious Activity Detected
You appear to be using software associated with or exhibiting bot-like activity. This is banned for security reasons. If this is a legitimate access, please E-mail gopher@floodgap.com with an explanation.
httpi/1.7.2 (nano_inetd_turbo/AIX) by Cameron Kaiser"
Please do send me the explanation. The proxy gets a lot of crap from bad bots (which in turn can make it burdensome on downstream sites) which requires controls, but the heuristics are just that, heuristic. If there's something to whitelist, I will.
FWIW, I got exactly the same message, and all I did was click the floodgap.com link in spicybright's post. Floodgap.com has never seen another request from me so I don't know what it could be detecting. I'm just using Microsoft Edge on Windows 10.
A gemini client would be a cool next step for this:
https://gemini.circumlunar.space/