I'm very unlucky so a lot of the time i get hit by missiles. I know you can place tnt crates and potions to block the missiles and i do do that but sometimes the missile hits me even though i placed an item behind when it was close to hitting me. Is there a consistent timing i need to learn or what?

Well, if you place it too early it can be that the missile simply goes round especially if a tight corner is coming up... so best to place at the last moment possible. Though to be frank, I never had problems with missiles, and your CTR pb run suggests you're still new to speedrunning it, so once you get better you get out of the "danger zone" faster.

Go fast, you'll eventually get out of the missil's range