How to Secure a Linux Server and Website Project [WIP] [Learning Project]

I plan to do the same post in a few different forums to receive different opinions and I don’t speak English natively, I hope this isn’t a problem. I will be grouping and placing all current learning links for secure linux server and website security in this post in an organized manner.

My Goal is to build a 1-3 Landing Page to sell Houses like this. (1-5 Images, 1-2 Videos, Small amount of Text) I need a ultra speed website because i going to pay for advertisement on google ads and if i have a fast website i end up paying less to advertise + better experience.
My Involve knowledge (Angular 2 and Typescript 2, i started Node.js but stopped at the beginning) I plan to go back to studying in the future to make a website on NGNIX using node.js and mongo DB or any BD better for those languages.
Since I don’t intend to learn code at the moment, I plan to make the website above using (Ubuntu 20.04 + CyberPanel ent + LiteSpeed ent + Redis + PhP + MariaDB + CloudFlare + Wordpress + Elementor Pro and use Google Cloud because its the closest server to me)
I have no idea how much about security I will need to know to make this landpage without my wordpress being hacked or my clients’ information like Name, Phone or Email being hacked)

Idk how to edit post here so i willl just put the details here if you wanna understand more about my problem.