Although it is not too late to start, you definitely will be at a disadvantage to players that have been here for 4 or more years
I would recommend joining one of the three "Classic Servers", them being Ector, Lamorak and Gareth.
These servers have only been active for about six months, so the player base there is new. The real problem with this game is that the majority of players have been here for years, and that it does not attract a bunch of new players.
The benefits of the Classic servers are that everybody has to start at level 1 and level up (on most other servers, if you have a level 50, you can skip directly to a Level 20 toon), so there are usually people to group with.
Catacombs has made leveling easier (this is an expansion pack to the game), and you will be able to level. finding a guild is not that tough, but getting in a good guild with a solid alliance is very important in finding others to do stuff that a solo can not.
If you are looking to join this game, I would say ask yourself what you like doing best. If PvE is your thing, this game is subpar, but if PvP is something you would like to do, then this game many consider to be the best. The battlegrounds are a great way to get a player oriented to PvP (but you have to be level 20 to enter Thidranki (level 20-24 battleground), there are ones you can join earlier than this, but hardly anyone is ever on those.