Most everyone uses the addon Questie, and it’s very helpful for speeding up the process. At some point when I needed more motivation/optimization I started using this guide https://classicwow.live/leveling which is very helpful for optimizing travel and skipping time wasting quests. It’s also free. I would say it definitely sped up the 40s and early 50s for me. It’s not perfect - sometimes the quest would be too hard for my particular class, and if you start in the middle like I did you might find that it’s not worth it to catch up on a quest chain or whatever. But would use it again for sure.