It is also worth noting that World of Warcraft Classic isn't exactly an archive from 2006. It has been rebuilt from patch 1.12, using modern data architecture and reaps the benefits of the modern engine. This means a lot of non-controversial quality-of-life features will still be present and it is possible to run WoW Classic servers on modern server architecture. As you can imagine, much has changed in the last 13 years in the tech space. That's before smartphones were even a thing. The modern engine no longer allows certain behaviours that could be used to get out of bounds, also adds widescreen monitor support and accessibility options! However, it does have the disadvantage of not being able to run on 32-bit systems which isn't that kind to older systems considering the game is from 2006.
Furthermore, we highly recommend you plan in advance regarding the class that you want to play. In the Classic WoW, there were no class specs. Every talent point spent couldn’t be changed without first resetting all of them and the talent point reset was a costly practice. If you already know what you want to play as in the end game – try to develop your talent tree accordingly. This way you’ll be able to save a lot of gold in advance.