Blaseball is big and weird and there's no one right way to experience it or learn about it. The best thing to do is just start watching games on the website then jump into the discord and start talking to people. If you need a little more guidance, here are some tips and links you can click on depending on what you're most interested in.
Blaseball: the story so far is long and wild. Here are some recaps:
Want to get involved in storytelling about the players themselves?
Okay, nerd. You want to see the numbers go up and/or do data crimes.