I think plastic reels might be best for starting out. I have recently decided I like steel reels better, but adjustable plastic reels will let you develop different formats without buying too many extra reels. There is plenty of time to buy extra stuff after you get hooked, and it will happen.

When I started, plastic reels required less thinking, and I thought they were easier. It didn't help that our instructor didn't tell us how to load a steel reel, so I tried to slide the film in as if it were a plastic reel that did not ratchet. That did not end well.

After playing with steel reels, I quickly learned they don't require much thinking either. I sacrificed a roll of expired film to practice loading in the light, and after loading about 5 times felt confident to do it for real in a dark bag. Of course, I practiced in the dark bag before using any film I really intended to develop. I don't develop much film, and have used steel and plastic about an equal number of times, but can now load steel faster than plastic.

Regardless of which reel you use, practice in the light and watch closely to how it works. Learn how to feel in order to tell whether the film is properly started on either reel.
Mistakes are the best way to learn, but you don't want to ruin film (unless your experimenting on the film). So, when you can load the reel well, purposely load it wrong and also learn how to feel for this. By only touching the sides of the film, you should be able to tell by how the film is moving into the reel and whether it is seated correctly. If you can reliably do it wrong, on purpose, you're more likely to avoid that specific accident, and will know how to recover from it if it does happen.
Then practice with your eyes closed. Then in the dark or in a dark bag.

I've some steel 110 reels, though haven't developed 110 yet. They are difficult to get used to, so I just take some expired film and practice while watching TV. I've gotten pretty good at it, and will have no reservations when it's time develop my 110 film.