Hey how do you get Dalton?
The start of dalton's storyline is by getting the job at JCS (check jobseekers on the PC). When you get to the level 2 of the job, you'll get a chance to romance him. Please note that in order to start the romance with him, don't start the romance with Garrett.
At this version (0.18) the romance with Dalton is unfinished, it will be finished in the next update. I'm working on it.