There are a lot of free web hosting services. Some of them are ad supported, other provide basic resource and require you to upgrade to a paid service at certain levels of server load. All of them share the same basic concepts you will need to know.
A certain amount of disk space will be given. Unless your website is geared towards the use of large files and images, you will never have to worry about exceeding your disk space allotment.
Bandwitdh is used every time a visitor to your site loads a page and/or an image. This is usually where the free hosting services impose their limits. If your website grows, your bandwidth usage will increase in proportion. Once you hit your bandwidth limit, the host will most likely temporarily shutdown the site until the next month or you upgrade the package.
FTP, an acronym for File Transfer Protocol is how you transfer files to and from your website. Using an FTP client you can connect to your FTP server using your account and upload your files. Alternatively your hosting account panel should also have a method of uploading files using a web browser.
For those that don’t want to or can’t create their own websites, a lot of hosts come with free website creators. Choose a template, enter some content and the website is created for you. These templates tend to be standard with the premium templates available at a price.
Every hosting account free or paid comes with its own email addresses. These can be mailboxes on the server with your account name or they can be forwarders. A Forwarder sends any mail to that address to another email address of your choosing.