There is nothing special about flying in rain, or snow for that matter. Plane flies pretty much exactly the same. The concern are other things that can be associated with precipitation - in particular, IMC, downdrafts, icing, and hail. Look at the weather and forecasts carefully. If it is truly light rain, with no T-storms, and good visibility, no reason not to go. With weather like that, the ceilings will be your biggest concern.
In general, it is always best to be flying INTO weather. If you get uncomfortable, you can always turn around. If you choose to press ahead, have a field you can make directly, still VMC the whole way, in back of you. Experienced pilots make long trips by finding short stretches that are safe, then working on the next one. Big part of Airmanship, at every level.
Note: If you do call flight service for a briefing, don't be shocked if you hear "VFR flight not recommended" if the forecast is for anything other than ceiling and visibility unlimited. You may want to have someone else's opinion (like your CFI) as well. If you do hear that, look at the weather and you plans extra closely.