Ok, first off don't build triforce. The standard for Ezreal is Greaves BT PD LW GA (situational item). If you feel you are doing no damage you probably arent autoattacking enough. In fights you have to keep autoattacking.
About the person saying not to build PD due to innate AS steroid, it give s a lot of other benefits and the AS steroid just makes them that much better.

tl;dr Autoattack more.

Maybe it's the build, I don't know. I build Ezreal different almost everytime, but if you wanna know how I carry all the time... In the beginning, boots and pots of course. Position yourself well, and poke with Q. Normally, I don't even get W. It does no damage, but slows attack speed. go back, always build phage first, with a basic attack, or a Q it could slow them. From there, build trinity. After trinity, I make the decision of buying a Phantom dancer, or a BT. If I go phantom dancer first, IE comes right after. If I go BT, phantom dancer comes right after. After that, what I get next depends on what the other team buys. If they have armor, I get a LW. If they don't have any armor, I but IE if I didn't get it, or if I bought my BT and PD, I buy more life steal. I normally don't know what to buy after that, because I rarely ever get there, the other team ends up surrendering. But by the time you buy your PD and IE, you should just auto attack.

I was going to say something like this. It's not that he's a no brainer roll your face on the keyboard and get a penta kind of champ but he is really really safe. His quick poke and built in escape (if you use them correctly) give him a strong laning phase. It's true his late game isn't the best but sometimes there's not going to be a late game if early and mid go your way.

Couple quick tips:
I don't play Ez myself but I do play against him often so I won't comment on building him much. I'll just say that going BT first isn't always the best idea. If you are behind building a bt isn't going to change that much. Like so many other things in this game it's situational.

You should try to keep from using your blink unless you are planning to all-in them. Ez is pretty squishy even for an adc so don't go panic blinking or trying to use it to dodge skills shots that you could avoid just by better positioning or sidestepping.

You gotta land those skill shots. There's not really a quick fix for this but being able to land skillshots is the difference between poking and just wasting mana. You should try to study your opponents movements as they last hit, most people (adc players especially) are pretty methodical about their last hitting. Having an idea about when they are likely to zig instead of zag should help you land skill shots. The more thought they have to put into dodging skills shots the more likely they are to miss cs and you can start to pull ahead. Keep in mind however that you shouldn't sacrifice cs yourself to poke at them unless it's going to lead to them getting hard zoned for an extended period.

If you or your support run out of mana expect to get bullied. This is true of most champs but Ez especially is pretty toothless without mana. Flask can actually be a decent starting item if you are planning on spamming a lot of spells.

It could be a warmogs rush, a lot of bruiser(AKA tanky dps) Are building warmogs first item, each bar on the HP bar represents 100 HP so if they have a lot of bars it could give you the illusion that you aren't dealing a lot of damage.

Like I said in the previous post you want to deal the most DPS you can on your ADC without dieing. BT is going to help and after BT you want the attack speed from PD so you build it as your second item. Triforce was popular in season 2 but in season 3 it's off on Ezreal and we go BT now. Most every game after PD you'll need LW and after that GA so you dont get 1 shot by someone and have the revive proc if you mess up. Also you can start with shortsword (i think thats the name) and 2 hp pots, build into vamp scepter get boots 1 finish BT get greaves go into PD.

As for your spells go Q level 1 E level 2 don't get W unless you have to. The max R over E over Q over W. Your E has the best scaling on your abilities, and if you know you can kill the opponent you can use it offensively.

Make sure you have AD reds and quints, armor yellows, MRes blues.

I honestly never build a TF anymore on Ezrael. I typically go with the usual carry build (Zerkers, BT, PD, LW), and then either grab an IE or an Iceborn (which, in my opinion, is far more relevant late game than a TF), and then either a Warmogs or GA. If I buy a GA, as soon as it procs (and if I have enough gold), I sell it for a Warmogs.

I'm getting mixed answers TF or BT. Is it situational or like always get BT no matter what. If its situational what situation should i get TF over BT

It could also be your internet connection. Since he has 2-3 skillshot moves, it could be a bit harder to hit someone with a lot less ping than you.

I only played him twice (during free week) and I knew that you have to play him with a lot of skill (I was actually surprising myself there) but I only managed to hit the enemies 40% of the time because my ping was above 100. The second time I absolutely pwned with him because everybody's ping was the same as me (27/2/19).

But yeah, just play him like you would in a ranked match and you will probably kick a55 with him.

Ezreal may very well have a high learning curve. I don't know. I do know I suck at ADC, bought Ezreal and proceeded to get a Pentakill in the first and only pvp game I've used him in. I don't get penta's with characters I'm good at so take that as you will.

Just go with BT.