I wouldn't really worry about flying through rain. Only real things you have to worry about is freezing level and heavy rain, which you shouldn't be encountering heavy ran unless you like flying under Thunderstorms - and in that case if you do, you don't need to be flying anything.
I've flown through rain twice, although 1 was on an IFR flight plan but the rain wasn't near bad enough to restrict the visiblity I was in (I was in VMC at the time).
Main thing, just make sure its not freezing at your altitude if you hit rain. Although only being a PPL you shouldn't have to worry to much about it.