Where to buy

Just passed my CBT and looking to book my DAS ASAP Started looking for bikes and found superbikefactory that had loads of choice and seems decently priced. But now seen lots of people saying to avoid at all cost, so where would you advise to get a first bike 600/650cc I don't have social media so don't think I can use Facebook marketplace. I'm in South Wales but can travel if needed

Thanks in advance