signed up for a 10k in november with zero running history, talk me through it

my colleague signed up for the bengaluru 10k and i said "me too" in a moment of weakness. that was 3 days ago. i have not run since school sports day. i can walk fast for an hour without dying. i cannot run for 3 minutes without my lungs filing a complaint. i have about 9 weeks. is couch to 5k then stretching it to 10 a real plan or am i going to injure something. also what do i do about the fact that everyone in cubbon park at 6am looks like they were born running.