If you need a quick-and-dirty HTTP server that doesn't need fancy configuration, try some of these one-line HTTP servers in languages like Python, Ruby, and PHP. Some examples include a small script that allows you to embed the server in to your program and add more customization. These are not intended for production use.
Let's Encrypt is "a free, automated, and open Certificate Authority." They provide free signed certificates as a trusted certificate authority. This tutorial walks through the process of installing certbot and requesting new certificates and renewing existing ones wit Let's Encrypt. If you are just looking to generate your own quick self-signed certificates, check out my tutorial on creating self-signed SSL certificates with OpenSSL.