Why does the site keep crashing?

Recently, my site is no longer working steadily. All the time there are some errors. I can not understand the cause and sequence of actions on how to configure everything? Will I really have to go to a specialist?

The author, do not get upset and jump to conclusions. I, too, faced with this and can give you suggestions for solutions that actually work. Try to go to this service and learn about the website error checker https://pr-cy.io/ With this service, you check the site and get a full report, where you will see the causes of errors.