You can only host and store files, static sites and workers with Cloudflare, they're not a full fledged hosting company.. at least not as of today.
I would recommend finding a good host with good nvme storage for higher iops, memory and CPU speeds of 2.5Ghz and above as PHP is cpu-bound. Consider your primary market and regions, and pick a web host based there then accelerate/protect with Cloudflare. So if in EU, pick NL or DE as they have the best transits and internet exchanges with sub 2ms connectivity to Cloudflare.