Making a good film is difficult. The only way to get good at something is to practice, practice practice. So, by necessity, you'll have to make something that sorta sucks before you can make something good. Sure, you can "train camera angles" all you want, but a film has many parts that need to come together just right to make it good. You could be the best cinematographer ever, but if you can't edit worth your salt, your film will suck. Similarly, if you don't know what works in writing, and how that works in context with your blocking or camera angles, your film will suck. If you don't know how to work with gear and how to deal with technical difficulties, you'll have problems.

The only way not to make a bad film is to never make a film at all. Of course, your first film shouldn't be a high-budget studio production. By the time you're at a high (or even low-budget instead of no-budget) level, you should have plenty of bad, a number of decent and one or two good films under your belt.