Why?
“The big secret in life is that there is no big secret. Whatever your goal, you can get there if you’re willing to work.” – Oprah
You can only do so much without particles, and the particle は is the most useful when it comes to noun sentences (like the ones you’re learning here).
By learning this particle, you’ll be able to expand on your caveman-esque です sentences and make them into something a little more natural. Learning this particle will also allow you to use several other grammar points that we’ll be learning throughout this season.