How can I check to see if everything is cached properly?

So I opted for a “ee site create --wpfc” install of Wordpress. added in PHP7 and LetsEncrypt Then followed the text in putty to setup W3 Total Cache as it said

I even went and created a swap file for MariaDB (I think) so that I don’t have any 'can not connect to DB issues) if I get a spike in traffic. I also ‘optimized the db’ by changing the number of workers or something too (these tutorials are strown all over the place so is difficult to remember what has been done and what hasn’t been done).

I was curious if there was a way to test and see if my WordPress install is caching everything it can in the most optimized way.

My current setup has 3 websites on a $5 Vultr VPS instance but they are non critical websites. I tried doing a setup on my three critical site this past weekend and ran into database connection issues with my biggest one.

So I figured it would be best to start small (even though this is like the 25th time I’ve installed EasyEngine just trying to learn the system).

So, the question is whether or not there is a way to find out if things are cached properly. Like, everything that can be cached, to be cached.