Diagnose WordPress Website issues along with the server

Hi, First of all I want to tell you that this issue need to be fixed along with the system admin level knowledge person,not only the WordPress developer. So please read the requirement carefully. I've a website that's running normally, having sufficient speed. But sometimes , may be once in a day or once in a week , that's very random, my server went down for high CPU utilization. I'm using Cloudflre DNS and when this scenrio occurs, I'll enable Under attack mode and then the utilization goes to normal. But there is an annoying captcha solver will show to every user. So majourity of the users will not solve the captcha and they left. So I need a perfect person who can diagnose the issue and fix [login to view URL] issue might due to bad sql queries, poorly written code , datatabse or web server configuration mistakes etc. The server is CentOS 8 and Webserver is apache running with MySQL. I know some things I didn't mentioned here. You can ask me in the chat. So please quote those who can deal with this [login to view URL]'t just copy & paste bids from your clipborad, seriously. I'll block.