I'll be honest, I don't think that would be good enough, not for outdoors. Ok to practise through.
Having said that, when I first started gigging properly (25 years ago) our singer had the obligatory HH 100 watt PA and a pair of speakers and it was good enough. But we all had proper amps, 100 watt valve marshalls and 150 watt Trace with 4x12 marshall cab and acoustic drums. so the PA only had to tackle vocals. We did some outdoors stuff like fetes and it was good enough to play to the small crowds that gathered.
My current bands rehearse in my studio (it's a giant shed!!) with a 400 watt Peavey powered mixer , electric drums and everything goes through the PA, (guitars use line 6 Pods). It's great for rehersal but lacks all sorts of oomph.
There's a lot of good gear available at reasonable money.