First showed up as a verb in the fourteenth century and a noun in the sixteenth. Comes from the Old French eventer and the Vulgar Latin exventare, a mix of ex- (out) and ventus, wind. Interestingly enough, it is not related to the words with the suffix -vent. It’s here just because.
Showed up in the late sixteenth century. Came from the Middle French event and classical Latin eventus (same meaning) which itself comes from evenire, to occur. Evenire is a mix of the prefix ex- (just like vent used to be) and venire, to come, which is also the origin word for venue.
Showed up in the late fifteenth century. Invention actually came first, but both can be traced to the classical Latin invenire, with basically the same definition. It’s a combination of in- (shockingly enough, it means in) and the above mentioned venire. So…to come in. I guess an invention comes inside a brain, right?
A relative latecomer, not showing up until 1742. It comes from the classical Latin adventus, again, the same meaning, although it also was specifically used in the Christian church to mean the coming of the messiah. Adventus comes from advenire, a mix of ad- (another word for to) and venire, to come, making it “come to”.
Showed up in the early fifteenth century from the classical Latin praeventusand praevenire, anticipate. Pre- of course means before and venire…well, I’m sure you’ve gotten the point by now. Anway, it’s “to come before”.
One of the earliest -vent words, having showed up in the early thirteenth century. It was covent in Anglo-French, back to convent in Old French, and conventus in classical Latin. It comes from convenire, the origin word for convene. The prefix con- means together, making it “come together”.
Showed up in the mid-fifteenth century, from the classical Latin words circumventusand circumvenire. Circum- means all around, in a circle (it’s related to circus). With venire, it means “to come around in a circle”, which is a pretty good definition for circumvent.
It showed up in the early sixteenth century from the classical Latin interventionemand intervenire. It’s a mix of inter- (between) and our friend venire. So, to come between.
Yeah, I was shocked to hear that this was a word, too, but it’s basically another word for a grant. It showed up in the early fifteenth century, coming from the Middle French subvention and Late Latin subventionem or subvenire (to help). The sub- means “up to” in this case, so the word means “to come up to”. I guess you have to take it figuratively.
There are also words like solvent and insolvent, which come from solve, not vent, and fervent, which has a completely separate history.
TL;DR: Vent and any word related to solve aren’t related to -vent words.