All you can do is go and look round a school and get a feel for it. Do the kids look happy? Are they engaged in lessons? Are they joining in with extra curricular activities? What is the staff turnover like?
If there is evidence, bullying is easy to deal with (CCTV, screenshots of messages etc...) so parents are called, pupils spoken to etc...
Online, you're always going to get parents who say don't send your child to a particular school bullying is rife, the SEN help is awful etc... but as a teacher when I read these messages, it is almost hard not to laugh when you know the other side of the story.
e.g. a dad was saying online that his son was excluded for a few days because he brought pork chops left over from the family BBQ to school and a refugee child got offended. What the dad failed to mention was that he waved the pork products in front of this child's face then threw the pork chop at him!
Another parent always slags off the SEN department at school. But in reality her son was really violent, and despite being offered huge amounts of support, he constantly told staff to f*ck off and would push tables over if he got angry. The school even paid for external provisions as he badly beat up another child. The boys own brother said it was because his brother got to do what he wanted at home so wasn't used to being told no.
So ultimately, go and look round the school, and get a good feel for it. That's much better than reading stuff online or even reading Ofsted reports.