To increase the loading speed of the online store on 1C-Bitrix

In the opinion of the PageSpeed catalog pages, for example – domo-terra.ru/catalog/dve... not the best download speeds :)

1. We need to get to the green or even orange area PageSpeed domo-terra.ru/catalog/dve... when assessing the MOBILE version
2. What we can do?
3. How long?
4. How much will it cost?

For a permanent job looking for a programmer to 1C-Bitrix to understand how we fit together lets start with this tasks:

PS If you work with some sort of online stores on 1C-Bitrix, write who can I contact to find out reviews about you. A decision will then be much faster:)

Thank you.