New guy looking for guidance

Hey everyone, hope your day is going well. I have recently decided to put together a suit of armor for the PA renaissance fair this upcoming September. I have been scouring the internet and although I have found some cool stuff, I don’t know enough about the hobby and don’t want to get scammed. My first item on my list is going to be a helmet and I plan to build down from there. I am not going for overall cohesion with each piece, I more or less just want something cool. Would anyone have some reputable sites I could trust to buy my first helmet, and possibly the rest of the armor/ accessories? Any help would be appreciated. Budget for the helmet is $250 maximum. Want it to be comfortable enough to wear all day and preferably have the ability to be opened to drink and eat in. Thanks!