Adding your first monitor takes about five minutes and needs no technical knowledge. You do not need access to your server, you install no plugins and you paste no extra code into your site. All it takes is the address of your website - the one you type into a browser.
We have collected the questions we hear most often from people setting up monitoring for the first time. Have a look at what is covered here and see whether it helps.
I updated the plugins, clicked through the site, went to bed. Three days later it turned out the form was not sending mail and the site was loading twice as slowly. Here is exactly what I have switched on today for my own site, my mail and my NAS - and why "the page opens" is the least useful piece of information in the whole set.
I run SEO for several dozen clients, and for years I learned about outages too late - from a "something is broken" e-mail or from a drop in Search Console. Here is how I arranged monitoring for client sites, and which features genuinely save my life.
I maintain a dozen or so client sites - Drupal, WordPress and a few things written from scratch. In support you learn about problems as late as it gets, and the last deployment always takes the blame. Monitoring gives me a timeline of what changed instead of guesswork.