Anyone know how to remove the chat panel that pops up when i press either “T” or “Enter”? I want to make it more like Java.

Buy Java. It would cost you less than Bedrock if you plan on buying something from the marketplace. Java does not have the Marketplace, Emotes etc… No paying for skins, worlds or mods. If you still want to play with mobile/console players make a Java server with Paper and add the “Geyser” plugin.