On new location when I've visited it for the 1st time there was only 1 scorpion outside, and it immediately started running away from the the location after I entered it. The re were no other enemies both outside and inside the cave.

On the second visit there were other scorpions both inside and outside. The same scorpion outise tried to escape again, but I ran towards it and it noticed me and ran towards me to attack me rather than running to the exit grid. Other scorpions outside were passive, and only hit me once if I literally stepped on them.
All scorpions inside the cave were hostile and literally swarmed me, though, much like the Golden Geckos on Random Encounters do.

There is no way to exit the cave and go back to the Forest/Entrance, though.

Also the cave feels a bit empty. Maybe add some loot? A corpse of unlucky traveller with some items, maybe, or a few chests with treasures?

Also, are corn plants supposed to grow inside the cave? Feels weird.

Will there be caves with other creatures later?

I could suggest some light sources, like burning barrels / torches, puddles of glowing goo or a fireplace inside teh cave. Would look great, but of course only if there will be human enemies (or even hiding neutrals?) inside. The pests won't like the fire (but green goo - maybe).
The current light level is fine even without additional light sources, though. All of the above is not necessary, but just will look good, imho.

I actually really like the cave. Wish I could explore The Glow from Fallout 1 in first person perspective... But since it's Fallout 2, I guess I'll have to do with... Dunno. Mariposa Military Base? Wanamingo Mine? Or, rather, Rat Caves under Klamath?