If you have only used digital point and shoot cameras then a manual focus, SLR, 35mm camera will be completely different to you. As many have already said, manual focus cameras can be fairly easy to focus properly since they usually had focusing aids to help you focus the lens. But they will not be very fast, especially if you are just learning. A good autofocus SLR film camera can be quite easy to use and will be much better, and faster, than a digital point and shoot.
Many of the people on this forum, myself included, have been using film cameras for years and manual focus is not new to us. But for someone who has never used it before it will be slow to use. If you only intend to take pictures of scenery, landscape, flowers, macro objects, or very slow moving things then you won't find that a problem. In those cases manual focus can actually be better. But if you want to take pictures of kids, sports, pets, or other quicker moving objects you will get frustrated pretty quickly. After years of practice a lot of people can get good enough with manual focus to keep up with fast moving objects, after all people were taking sports pictures way before auto focus was invented, but learning to do that takes practice. Of course, one clear advantage to manual focus, when you get the lens focused on something, you know what you focused on. Some auto focus cameras can pick something entirely different to focus on then what you intended, and unless you are watching closely you may not realize it while you are taking pictures. Only later when you get them developed will you realize that some of your shots are out of focus. That may also be what is causing you trouble focusing your point and shoot camera.
I love Pentax because the lenses are so interchangeable. You can use lens from almost any period on any Pentax camera from around 1977 on. Nikon is almost as nice in that respect and their auto focus cameras tend to focus much faster than most other cameras. The advantage with those two camera brands is that you will be more likely to be able to use the same lens on a manual focus camera as well as an auto focus camera, if you do decide to try one or the other later on. Canon, Olympus, Sony, etc. make magnificent cameras as well, but their auto focus and manual focus equipment don't usually play with each other very well. What I mean is that their manual focus lenses won't hook up to their auto focus cameras, and vice versa since they changed their lens mounts throughout the years.
Like others here, I suggest that you go to a reputable camera shop in your area (not Wal-Mart or Best Buy) and try the different types of cameras they have, auto and manual focus, to see which you find easier to use. Some of these shops will even let you rent equipment for a weekend which gives you a terrific opportunity to try things out. Of course, most of these shops will be selling new digital equipment but they should also have used film equipment available to try out as well. New film cameras are pretty rare anymore. They are available but are most frequently the lower quality, manual focus equipment. Holgas, Vivitars and Nikon FM10s come to mind. There are also some VERY expensive, high quality, film cameras out there as well, but they are probably not the best way for you to start out unless money really is not an issue for you.
I would suggest that you start with a 35mm camera. Medium format is also very nice, but the film is a lot bigger, more expensive, and more expensive and difficult to get developed. The cameras for medium format film are almost always much bigger and bulkier to carry around and use as well. Of course large format is also still out there, but it comes in sheets, not rolls, and takes a totally different style of camera that is far bigger than either of the other two types. Depending on what it is that you want to do, medium format and large format can certainly work for you, but they are not usually considered the best way for beginners to start out and learn on.
I hope all this made some sense and helped you out a little.
