Newbie - which weights should I buy?

I just signed up for PLUS and am so excited. I am a moderately-in-shape female 32 yo and 130 lbs. Can you please recommend which weights I should buy for training? Options include 3, 4, 5, 8, 10, 12, 15, 20 lbs. I can buy up to 5 different weights. Thank you!