Long page loading time, what could be the reason?

Question

CDN

In Yandex Metrica, I started looking at the parameters for loading DOM pages, the results upset me, although it is clear that I use ordinary shared hosting.
Yesterday I rewrote DNS addresses and configured CloudFlare, but the results do not change for the better. Search queries 98% from 1 CIS country.
As for moving to a VPS or another CDN, I don’t have the money yet, so I use a free tariff plan.
Tell me where to look to optimize page loading?
ps Please DO NOT advertise CDN services, the Internet is full of reviews.