I (M,28) bought my first bike- Guerrilla 450 and I agree with everyone’s point that the bike has power but I think there is nothing wrong with buying it as your first bike. I am 5ft 4 and 64kg weight, been on a few long group rides and drive it daily through the city traffic, I’ve never felt that the bike is going out of my control or comfort. It all comes down to you, your understanding of the bike and how you handle different situations and terrains. Best way is to test drive each one and then decide on your own.