For the round 15 and round 30 on all maps speedrun can I start the maps in any order I'm guessing I could?

Exactly. I'd say do the hardest maps first to save time restarting difficult sections

also i have other question when do i change maps when i see round 15 white or when its red?

Any round 15 speedrun ends the moment the round number 15 shows up on screen. The graphic animation means nothing, as long as the number is there