My first ever 10k today - 47:41 want to get it down to sub 44

Hey, I normally run 4.5 miles twice a week (I'm 16) but today I signed up for the New Year's Day 10k in my town, I really want to get into the top 3 for under 18s (there were 450 people last year) so I need to get sub 44, I feel like if I push myself I could knock off another 90sconds then on the day with all the motivation another 30 but I want to get this time as low as I can! I'm planning on running 10k 3 times a week wed fri and Sunday every week for the next month to try and get my time down, is this a good idea?

EDIT: I meant 48:41, damn