"The little things you do..." part means the ways you help Fate find you a mate. So, in other words, you can't find a mate by sitting home every night and weekend: you have to go out, talk to people, join groups, participate in activities, etc. These things "help" Fate in finding you a partner.
"Crush" here means a person you are attracted to; "nudge" means to slightly push in a certain direction.