What can I do to reduce TTFP & CLS?

I am running a pretty large store on wordpress. I have cloudflare pro APO installed and I’m running rocket loader and most other performance options.

I’m also running wp rocket for js deferring and minimising and a few of their other basic settings.

My CLS and TTFP is still a “fail”

Should I move my nameservers to cloudflare?

What else can I do to improve it? My website is www.forestsuperfoods.com.au

Thank you