You joined the TDS community recently, and now you can't choose what tower to get. Fear nothing, because this post will help you know what towers to get when you are starting out.
Since it is early game, you will of course have the 2 towers: Scout and Sniper. You also start off with some coins, but you should save the coins for later as most of the towers in early game are complete garbage. You should never buy towers that have golden skins (Except for Minigunner and Crook Boss, which is a Level 30 unlockable tower) Your first tower you want to prioritize on getting is Shotgunner. Shotgunner has very high damage on a single shot, reaching over 100+ damage in only 1.5 seconds on max. During the grind for Shotgunner, the only mode you want to play is Molten. No exceptions. Molten is by far the best and the 2nd best for grinding coins and EXP. Molten gives 4x more than Normal and is way easier than Normal mode. When you are ready to start grinding for Shotgunner, do not USE SNIPER. Sniper is overpriced and does the same DPS as Scout, which is way cheaper than Sniper. Because of how terrible Sniper is, you are better off spamming Scouts to deal with the early waves and for the first slow boss. You are unlikely to die on Mystery waves, so do not count on RNG to save you. Once you reach 2500 coins, your next objective is to get Farm. Farm is by far the most required tower in the entire game (Events do not give any money, so do not bring it when you are doing events), being more useful than Cowboy. Since you have Shotgunner, grinding will be much easier, as you can reach Wave 40 if you get enough Shotgunners to deal with the zombies. Once you get Farm, your next objective is to get Dj Booth and Commander. This will allow you to solo Molten with no problem, which makes it so that once you reach the Molten Boss, you will not have to micro your towers to the back. Getting Commander and Dj Booth will not be as simple, as you will have to get them in 3+ hours since they cost 7500 if combined. Once you get Commander and Dj Booth, you will enter the middle game, where you will have to start grinding for levels and coins. During this time, you should get Ranger, Military Base, Minigunner, Turret and Ace Pilot. This will allow you to prepare for Hardcore, which is required for grinding Accelerator and completing the mode itself. During the grinding, the towers you want to get first will be listed in an order, with one being the first should be priortized first. Ranger < Minigunner < Military Base < Ace Pilot < Turret. Once you reach Level 50, you have the choice: try and triumph Frost Invasion (or another Event if Frost Invasion ends) or do Hardcore for Accelerator. Getting Accelerator is recommended, as it allows you to do Hidden Wave much easier and also allows you to do Events much easily. Since you have Turret and you are still in the mid game phase, you should consider solo grinding if you have nobody to play with. You should also memorize the wave structure of Hardcore, so that you don't have to overspend on defenses. At the same time, you must also learn the money glitch, which makes the wave bonus instead solo, not much lowered earnings, which is triggered if the other players have delayed loading into the game (One player should be in the game until the first wave passes). Once you start grinding Hardcore, there are 2 ways you can grind Hardcore: Following a Duo Strat getting to Wave 41 or just doing a solo strat, which allows you to get less gems but is still worth it if you don't have a friend to do Hardcore. Once you finish getting Accelerator, you will already have a large amount of xp earned from Hardcore, which will either be enough to get to Level 75 or at least 20 Levels from getting Accelerator. You can choose to triumph Hardcore and then stop to get the Deluxe Crate or you can choose to rather just triumph Badlands or events. Since you will have Accelerator, you will be in the late game, where you will grind levels and coins for Golden Crates, and Pursuit. Since you have Accelerator, grinding will be extremely simple, since Accelerator has extremely high DPS, outclassing Ranger. If you rather would just do Hidden Wave, then you should of done it earlier, since it is much harder than before thanks to the Military Base bug being patched and Toxic Gunner no longer slowing major bosses. If you managed to get Gladiator, grinding will be a joke since you can just get 2500 coins in only a single hour, which is way more than using Scout to defend for the early waves. After you have finished grinding for Pursuit and getting Hidden Wave badge, your last objective is to either just go for an extremely high amount of levels or to grind for Golden Crates. If you did not buy Pyromancer, Soldier and claimed Crook Boss and Cowboy, the chances of getting the best skins will be an extremely high chance. The reason why the 4 towers mentioned for getting a Golden Skin is not recommended is because of its terrible increases (Crook Boss is an exception, since it is considered a good Golden Skin), sometimes the damage increase does nothing, or it improves nothing useful. The towers you should never get for Golden crates is listed by what to get first. Golden Minigunner > Golden Crook Boss > Golden Scout > Golden Cowboy > Golden Pyromancer > Golden Soldier. Once you get Golden Minigunner, Golden Scout and Golden Crook Boss, do not grind for the last golden crates. They are not worth it unless you are doing challenges. After you have finished the entire game, you are in the End game, where you can carry noobs, do events, keep up with the community and just help others, and etc. IF this guide helped you, please comment. This post took over an hour to write.
In a nutshell, you should get Shotgunner as your first tower, Farm, Supports, essential towers for triumphing Hardcore, Accelerator, events, Hidden Wave Badge, Pursuit, and Golden Crates.