Conserve your political capital

Everyone, and particularly junior people, need to accept the painful reality that within any department and university they only have a finite and limited amount of political capital and goodwill. So, conserve it like a precious commodity. Only cash it in for things you really need: e.g., getting tenure, adequate lab and office space, a strong letter of support for an important grant application, a reasonable teaching load, promotion, ....

Don't squander your capital and goodwill with minor gripes/requests/demands about lab space, small salary increments, not getting exactly the teaching you want, minor irritations about administrative procedures,...
Middle (and senior) management may quickly get tired of these minor concerns and will then be much less sympathetic and willing to address major concerns.