I was thinking something similar. "Love & Rockets" is a title, but it encompasses a lot of varied stuff, including things that aren't titled  "Love & Rockets", like Measles or Whoa,  Nellie!. It's like if you said, "Sell me on John Byrne." That can mean different things.

So I have acquired (from the library) the previously mentioned Maggie the Mechanic collections. There are no references to were any of the stories come from, just that this is the 'first five years of Locus stories'. It claims them to be presented in 'perfect chronological order' (no idea if that means in story or release.
I read the first few and the art is nice (great in the first one, good but rushed feeling in the others) but I'm throughly confused.

The first story 'Mechan-x' is quite good... it feels like it belongs in 2000 AD to me. Fun story, vaguely future sci fi setting with some hints of some interesting overreaching stuff later, but for this 8 pages just a simple, fun story about Maggie and the first day at a new job. It's a bit dated, but perhaps it's supposed to be very 80s.

Next is 'How to Kill a' which is two creepy dialogue-less pages that I think maybe are meant to be Hopey writing something? Or creating a story, while the story is really creating her? Not really sure. Cool panels, but not idea what they are for.

next up is 'Locas Tabien' which is Hopey and Maggie (though to be honest I wasn't clear it was them again until 1/2 way through because the art is much rougher) seem to be at the library helping a new character look for books about witchcraft. They leave the library and go to a friends house then theres a fight and a flashback.
Here's where my head hurts.. the friend's name is Izzy... who is credited with writing the first two stories, so are those fiction about the real people? Or is it actually a vaguely sci fi setting? (This story had no scifi like the hover bike, just very 80s) If not, why do we have such opposite and unrelated stories? the 2nd one's main purpose seems to be a monologue by Izzy about a wonky bookshelf.

lastly for today is one page of Penny Century, who asks a weird guy with horns if she can be a superhero. That's enough for now... if I get much more confused I'll be giving up.

(comments/advice welcome)

It's good to bear in mind that at the time Los Bros were young alt-comics creators doing whatever came to them. They found their grooves relatively quickly, but the earliest stuff is very much seeing what sticks. That's why you'll see suggestions for starting a little ways in. If you want stability and continuity, that might be your best approach.

To me, that's where the greatness begins. The SF stuff, with adventures, dinosaurs and spaceships, was good fun that I could do without; in fact, I'm glad the French version of Locas skips those chapters entirely. It's with the stories set in Hoppers that Jaime gets into the major literary work leagues, in my opinion. He doesn't do a Garcia Marquez riff the way Gilbert does, but brings in a different flavour of magical realism.

The Death of Speedy Ortiz, the story of that black dog who might or might not be the devil, the powerful bond between Hopie and Maggie, the convoluted yet so banal history of the Chascarillo family, they all create a rich tapestry that no other title ever managed to create so brilliantly.

But then, as others have said, your mileage may vary.

(I also grew very fond of Gilbbert's Palomar, despite not liking his art at all at first!)

I think one of the things that gets L&R compared to literature rather than comics or genre fiction is that the characters aren't necessarily meant to be identified with in the same was as , say, the hero or heroine of a comic or even a detective novel are meant to be: so Maggie and the other characters aren't always going to be likeable but they are going to be interesting (for anyone who ends up enjoying these comics) in many different ways. One of those ways is as a faithful representation of the kind of real-life people Jaime Hernandez observed around him in his personal environment of southern California in the 1970s and '80s - apart from the SF/fantastical elements of some of the early stories - and even then, she's thinking and reacting as one of those people might realistically be expected to do assuming those elements were part of her world, as they are in those early L&R comics.

I don't think you're meant to dislike Maggie. She just struggles with self-confidence, especially in the early part of Love and Rockets when things don't work out as she'd hoped with Rand Race. One of her defining traits is that she's always falling for the wrong people, and then when she meets someone compatible she grows restless and leaves for no good reason. She can't fully commit to Hopey, either. That's a large part of why long-time readers were thrilled by the most recent issue of Love and Rockets (Nov 2023.) 

It's worth remembering that these stories have been going on for 40 years now. If you've read the series from the beginning to the most recent issue that's a lot of water under the bridge. It also covers a lot of phases in Maggie's life.