Let's face it, a great many film makers got into the business shooting fan films. You could make the argument that Raiders of the Lost Ark is a huge fan film based upon chapter series from the thirties and forties.
The film making is just as difficult as if you were shooting a film that you were planning to market and the love and care involved is far greater because all that you get in the end is to see the finished product. I have been a Star Wars fan for most of my life and there is probable a Star Wars fan film in me if I can ever find the money and someone who can pull off playing Ahsoka as a grey Jedi.
Back to the subject of this post. A fan film can become a digital film making classroom if you approach it the right way. The built in limitations of both character and situation will make you a better screen writer. The requirements of set and situation will force you to be inventive. You will have to learn to construct sets and do special effects that you may have not learned how to do otherwise.
Below is a bts video of the fan film. I know it is in German.
Thank you for visiting and I am still looking for showreels and acting reels for the page that I am adding.