Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.
Where to get materials and reagents you may ask? Buy for cheap off farmers in bulk or track Auction House lots. Get in touch with most big sellers. Communication is important here, send a whisper or write them a letter. It would be good for both of you to establish business relationships. Constant suppliers and buyers is convenient for both parties to save the time and effort.
Each pet has 3 abilities it can use during a battle, but a total of 6 to choose from. They will also have a total of 3 active spell slots that show which abilities can be used during a Pet Battle. The first spell slot will already be unlocked, but the second and third will only become available once the companion has reached a certain level. Other spells will also unlock after reaching higher levels.
This is definitely why we do a beta test. We can also do things like reset the realm at a busy time like 4:30pm PDT to try and find the source of a certain issue where a crocolisk is losing it’s brain due to how multiple processes are interacting and mirroring code to form a cohesive world. There were similar types of issues like this back in 2004 but we wanted to try and resolve this one before the weekend for the folks who are testing.
This is something that people really need to start to understand, not just for Classic or WoW but software developement in general. Fixing a bug isn't just flipping a switch or changing a single digit. You have a machine with literally hundreds of thousands of parts, designed by dozens of different people at different times over the course of 20 and more years. You change a single thing and it might break 50 other things in very subtle ways that might not even emerge until months later (i.e. the very high M+ keys some players got at the start of BfA).
I now have a Patreon Page where you guys can support me while I work on Vanilla WoW leveling guides every day. I appreciate all of you who support me on there, it means a lot to me right now. Doing this full time is taxing on my financial situation. My goal is to make the best Vanilla WoW leveling guides on the web and the donations keep me going at it healthfully. There is also cool rewards you get in return for donating. Thanks!
World of Warcraft (also known as WoW) players have highly requested the classic version of their favourite game. As with any game, changes and major updates are added over the years. Since August 2006, many changes to the game have not been received well: such as trivialising levelling up. The level cap will drop from 120 to 60, but contrary to how that sounds, it will be a far more grindy journey of fun and progress. The current developers have made levelling up very fast in comparison to the classic days, purely to focus on end-game content and raiding which many people do not enjoy. Prior to these changes, many people enjoyed the games for years whilst not hitting max level, something never seen in the modern edition of World of Warcraft. The levelling process was a journey, having fun with professions and the grind that is no longer found. Of course, there are countless other changes that will be reverted, as you might expect when comparing something from 2006 to 2019.