> But what with the worker_connections? I have read that this is the number of simultaneous connections a single process can handle. How high should this value be? I am expecting lets say 20 connections per hour. I will host there only my personal home page and my school notebook (based on Wordpress). Will increasing this value result in high usage of RAM by idling nginx waiting for new connections?

As echoed by others, I'd hardly be worrying about 20 requests / hour, but just FYI, that's a *maximum* number, so if you're not using it, it won't really consume more RAM. nginx handles many connections very well, so it won't really matter if you set it a fair bit higher.

Generally PHP/MySQL would be your optimisation targets as they'll consume way more RAM than nginx, but again, for your load, I wouldn't be worried.

> Should I set there something more to e.g. to make the file upload possible like with the phpMyAdmin or it will just work out of the box like with Apache and PHP module?

If you're uploading large dumps, you may wish to increase the size of client_max_body_size: http://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size