Slow ttfb on first load

Hello! So my problem is that my webiste load slow on first load, in the dev tools long waiting time to TTFB My questions is...What technical questions should i ask to my host to imporve sites load time...? I got an answer optimize your website, maybe it is true, but i dont know Technicly my site is joomla template, runs on cpanel. php 7.3 i have added site to on cloudflare and instal JCH optimize package, technicly site loads 5 seconds on first load time, than it runs good Thanks