Train for obstacle course race

Hey guys! Has anyone ever done an obstacle course race? I've come across one in my area that has a beginner friendly option - it's 3km with 15 obstacles and really want to have a go but it also seems properly scary because it is out of my comfort zone lol.

Today I had my first run session, I did 9 rounds of 1 min run, 1 min walk and felt like I could probably have continued but didn't want to overdo it on day one.

I have until April 2027 to prepare so would love to hear any tips or suggestions of programs/challenges that would be helpful (I have FB plus). Thanks in advance for any help!