First of all...World of Tanks matchmakers is specially design/program to award poor players with better teams and beat down the better players. The only way to get around this is to play with a platoon of good players. If you try to play by yourself, your win rating will slowly worsen in time. There any interesting online article called "WOT is rigged". It goes into greater details on why Wargaming.net owner has parented the matchmaker program.
Second, World of Tanks is all about your in-game statistics. If you ever reach a win average of 50% or better, then the better clans may offer you memberships. Which will open up clan wars, platoons, team fights, etc. Until then, stay away from clans with win average lower than 50%, for they will only drag you down.
Third, World of Tanks secretly allows players to use a mod named Warpack. It has a monthly fee and developed by another team of Russian game designers. It basically gives a player x-ray visions, count-battery fire again other artillery is simple since warpack will mark on the map where their are after they have fired. Allow you to fire at a moving target and hit the most critical area, remove trees and brushes from view, plus many other illegal extras. Don't go to World of tank forum and complain about this mod, for you will be banned from the forum and WoT game play. I was banned for a week myself for complaining. World of Tanks knows about Warpack and secretly allows it use. Either they share in the extra profits and there some other reason(s). Good news is only some of the higher level tier players use this mod...so you could be able to play in the lower tier without some players using this cheater mod.
Four, World of Tank is all about profits first and last. The game is design to make money. Free to play is a smart come on, but if you wish the advance quickly up the tiers levels and tanks, you have to pay for it. I have know players that spend hundreds of dollars monthly on this game. So, don't kid yourself, World of Tank is design to take your dollars in exchange for in-game gold, special tanks, camo, crew training, special equipment, in-game aids to the crew and better ammo.
Five, World of Tank clan wars is fun. In clan wars, there no matchmaker, its teams of fifteen players against each other. Everyone is using gold rounds, they best crew and all tanks are fully camo and gear up. All players need to play their best. Normally clans will have their combat officer communicating with their team on team speak and will have pre-battle training before hand. Remember, the best clans only recruit players with high win-rate of 51% or better. Some of the top teams will pay out in-game gold to their players that's corrected within the clan war campaign.
So if you want a good tank, try World of Tank. Its not a "free to play", by a long shot, but is fun once you reach top tier and have an excellent win-rate. You will need to find in-game friends to help you in platoon play. Please remember that you will need to spend year(s) of time and allot of money to pay. If this is you're only computer game, you could be able to afford it.