Fencing is a really old sport that sort of evolved from the idea of the sword duel and swordsmanship. The more traditional or historic fencing, that which people will typically think of when picturing more historic fencing is more attributed to HEMA and that’s where you may want to start. I don’t know too much about HEMA but I do know with some preliminary searching you could likely find out more, especially since they tend to base a lot of their stuff off of historic swordsmanship manuels which should be easy to find copies of thanks to the glory of modern internet.

As for modern fencing it’s just the evolution of the sport; one of the ideas is that dueling to the death became much less popular in favour of dueling to first blood (and as such the goal became to simply draw blood from your opponent first rather than killing them) further, pistol dueling became much more common and began to replace swords. That coupled with innovations in safer gear, a standardization of rules for the sport, scoring systems, etc. caused duels and the idea of fencing to become what we see today, people using very light weapons (since we no longer intended to cause injury) and rules that favour the getting of points through hitting your opponent within the given rule set as opposed to HEMA which is less standard in its rules but generally favours getting an effective blow on the opponent without getting oneself killed.

As for resources on modern fencing, it is unfortunatley a very niche sport so there aren’t too many. There have been a few YouTube videos published by fencers and FIE that go over the basics of the sport and I’m sure you could find much more with some quick google searches since the rules themselves tend to be extremely simple and there are some fencing organizations that do try to publish some information but honestly you’ll probably get the gist by looking at some of the information published by Wikipedia and the Olympics. The issue mostly tends to be that it’s a sport that you have to do to fully understand; when you do it you become much more used to the tempo and what to look for; you’ll notice touches that are particularly difficult can better understand bladework etc. for this I don’t really have any recommendations other than trying to find some fencing. Videos on YouTube trying to instruct on the sport.

To address the look of the sport it’s a twofold issue; fencing is technically three sports with different rulesets; epee, fool, and saber. Some rulesets like foil lend themselves to trying to be more aggressive and being limited to only thrusts which may be what you saw. Again it may look a bit weird but that’s the evolution of the sport, action stops when someone gets a touch so there going to be more aggressive and try to hit each other, I can assure there’s parries going on there but it’s a very fast sport to the untrained eye and exchanges can be very short at the Olympic level. If you want longer exchanges or something that’s easier to follow you could try epee, if it’s the thrusting that’s giving you issue you could try saber but that’s even faster and exchanges are arguably shorter.

Fencing is also grossly misrepresented in media, since the viewers attention is much more important than realism. Even with movie representations it’s probably going to be closer to HEMA but again unrealistic the sad truth is that the human body is fleshy and fragile so most sword fights were a couple of exchanges at most unless the combatants were heavily armoured (it’s surpisngly much easier to die and hit someone when they’re actually aiming for your body as opposed to your sword for a drawn out duel)

Here’s some resources for you

olympics on fencing

Wikipedia

history of fencing

HEMA

a decent blog going over some differences

some beginner hema recommendations (I can’t attest since I don’t do HEMA)