WoW it is MMORPG, so playing in this game solo not so funny, as it can be. But some people like to play on non official WoW servers, known as World of Warcraft private realms. Those worlds are best choice for players, who don’t want to pay for game or want play with their friends in friendly world. Also private servers are choosing players, who want play in the “old school” times – in pre-Burning Crusade classic World of Warcraft, in Burning Crusade etc. Classic servers with, for example with famous patch 1.1.12, are most popular. Players on these realms can return in times, where hardcore playing, farm and exclusive epic equipment was core of the game. There are a lot of different ways to make private-realm, but I recommend you don’t ignore nice opportunity play in WoW on official worlds. They usually unstable, bugged and don’t offer full functionality. Often on those shards quests don’t works correctly or bosses don’t have abilities.
How to choose?
If you want play on free World of Warcraft server and ignore all features of official, you have to choose carefully, looking for best variant. Read all comments about liked server, how often it goes down, have it any annoying bugs or disbalance because of donators or not-working abilities. Some freeshards offers opportunity to start at maximal level: 60, 70 or 80. If you are choosing those servers, you can loose a lot of fun. Try to choose variant with x100 or x1000 rates, if you want fast leveling.
Donate or not donate?
Sometimes privates offer more bonuses for players, who donate real money. Donating opens free access to the maximal level, best equipment or renaming character, Of course, if you are donating, your character can become more powerful, but aren’t better to pay this money to play in official? So I recommend you choose official servers, but if you can’t pay for play, free or pirate World of Warcraft can be only opportunity to see beautiful lands of Azeroth.