The video that Maklon provided, I believe, is for an "local" copy of moodle. But you will want your Moodle somewhere on the Internet.
There are hundreds of was to install moodle.
I suggest that you consider buying a VPS from a company, of which there are many, and learn how to get your server prepared, and then install moodle from scratch. This may take awhile depending upon your background. Alternatively, you can have someone else do it for you.
I run my own VPS (purchased from GoDaddy) for about 12 courses/year, about 500 students/year. Yep, there is an expense to this method. Depending upon your budget, there are other ways to run moodle. You can also consider starting with the free MoodleCloud platform, but for 300 students you will need to pay to upgrade it. 50 students on MoodleCloud is free. This is a good place to start for learning Moodle.