If you're looking to buy Gamestop stock you need to set up an account with an investing brokerage. Below are platforms you can use to buy GME, Some also include a sign up bonus. If you sign up with all the likes you'll earn over $100 minimum just for signing up and following the terms for each brokerage. You can use those sign up bonuses to buy more GME if you want!
Sign up here to buy Gamestop on M1Finance if you want to automate your investing. I personally use M1Finance and am a huge fan of the service. $50 sign up bonus.
You can't go wrong with Fidelity. Their customer service is top notch. It is where I hold my retirement accounts. This offer is valid for new or existing Fidelity Brokerage Services LLC ("Fidelity') customers who open through the following link https://www.fidelity.com/go/starter-pack and fund a new, eligible Fidelity account with a minimum of $50 on or after 01/26/2022 and have not otherwise previously taken advantage of Fidelity's $50 for $100 cash offer. Offer is limited to one bonus award per individual.
MooMoo offers an interesting application that offers helpful information when buying stocks that you normally pay for with other brokerages. There is also a social aspect where you can discuss things with other investors. You can buy GME stock on MooMoo. You'll be awarded a stock or two on signup.
Love it or hate it Robinhood will give you a free stock when signing up. The app is super easy to use, sign up here.