I think you are missing something important here - each of these blocks will run on every tick. You probably think that block 21 must finish it's work before going to block 22, but this is not the case. Blocks 21, 22 and 23 always pass, even if there is no trade at all.
Trailing Stop is the distance of the SL relative to the current price.
Trailing Step is how often to move SL. This value is normally much lower than Trailing Stop.
Trailing Start is the profit that the trade must make before doing something with it's SL. This is distance relative to the Open Price of the trade. If the price is above this level, then SL can move, otherwise not.
Again, no block waits for other block to do it's job. Especially these blocks, they pass every time even if they did nothing at all. Inside each of them there is a loop that iterates through all trades and moves (or not) their SL. There blocks does not communicate. Each of them is doing it's job and does not care what is connected after