I think it is a good idea to know why you want to try film. Just for fun sounds a bit strange - ordering film online, waiting for it to arrive, using an old camera, working with a limited number of exposures, not being able to see the result of your decisions until weeks later, finding a good lab to develop, scanning, waiting... Did you say fun?
By the way, I went down the same road a couple of weeks ago - bought film and started shooting for the first time in a decade. Some of my reasons included using film era lenses in the way they were intended to be used, trying different format and thinking. I was reading books on composition before diving in the film, and I think it is a good idea to do so. I found that reading books on composition and then shooting film improved my photography a lot. In the past I would snap away and then spend hours going through the shots thinking which ones I should keep and how I can salvage them, now I spent a weekend at my parents' place, and instead of a usual pile of shots, I was surprised to find only a dozen on my digital camera, and another dozen on my film camera. The thing is, the percentage of "keepers" increased significantly. With digital you spend time after taking the shot, with film you learn to spend time before the shot so that you do not waste it after.