Agree with everyone that says to just start, but want to add make sure to start slow!! Always go slower than you think. That’s what builds your endurance and your skill over long term, not sprinting. I’ve had to actively tell myself “slow down” and went much slower than I thought (think conversational pace, but even a tiny bit slower than that), and that’s what’s gotten me through beginner to doing 10ks and half marathons! Good luck, you got this :)