I've been paying more attention to the house of the moon than the phase, but apparently the phase of the moon at solar return helps set the tone for the year, and I see that in retrospect looking over my previous solar returns. It is, essentially, the stage on which everything else happens.
If your SR square is a first quarter moon, this is to be a busy year with a lot of need to work on/for something. It may be a time when you often have to just keep plugging away at things without feeling like you're seeing results. If it's a last quarter moon, it's a wrapping things up time. The work to finish something, to wind it down, needs to be done.