Migration of a Drupal 7 site to a new installation of Drupal 7

Hello,

I'm learning to work with Drupal 7 as I develop my website. It's time to completely update it (there are many modules, and the provider reports that the CPU usage from my site is very high), and I want to recreate the site locally from the old database, i.e., from Drupal 7 to Drupal 7. The site is bilingual (EN-RU), tmrussia.org.
Could you please advise me on the correct order of actions? How can I transfer it? 

I would be very grateful for your help. Thank you.

Gennady