Fluffy Chat is a bit easier to use, Element is a little more powerful but more complex. (I don't recommend Element "X" edition as some people have reported bugs with it)
These work on desktop, mobile, and web!
When you launch your client, it will ask you to choose a "homeserver". That just means where your chat account is stored. You can put it anywhere you want. Most people just choose "Matrix.org", but there are a lot to choose from (I also tried out Catgirl successfully). You can even host your own homeserver if you want, but that is more work.
Join the BlepStation space and add all channels there: #blepstation:rawrly.com (You can click the link or paste the text #blepstation:rawrly.com into your client's search bar.)