How to reduce TFFB on my wordpress website?

I rent server on AWS LIGHTSAIL ( with pre installed cpanel) and my configurations are

• 4 GB RAM
• 2 vCPUs
• 80 GB SSD

After Lightsails finish installation I start to optimize my WHM first (I optimize my security, turn off some service ) then I upload my website on Cpanel after that I open my website and TFFB was 1 secound + witch is A LOT, then I install few things like

• OpCache
• HTTP/2
• mod_pagespeed
• Gzip

And my TFFB is now between 300 and 400 ms and I want to reduce that to be between 200 - 300 or less, so my question is can anyone suggest me what to do more ?