Is fresh film being used? The first image suggests old expired film or possibly underexposed new film. I've seen brown spots with old poorly stored film. IF you are using old film, and it is tempting to try something new with cheaper film, try using fresh film - expired film can be fun, but early in the learning process it complicates the process; for example, are the "brown spots" film or development related?
The dust on your first film is probably drying related, and all of the previous suggestions other than photo-flo are appropriate and worth trying. We all are working in different environments with varying humidity, ambient temperature, water quality, etc and techniques that work for one person my not work for others. Another possibility is that at some point prior to scanning, your film came in contact with a dusty surface. I have obtained scans like photo #1 after accidentally dropping my negatives on what I thought was a clean floor.
The scratches on photo #2 could have occurred while loading the film or sometime after development. Like others, I don't recommend a squeegee, but I don't think these scratches are related to that as squeegee scratches tend to run somewhat parallel to the film, and the scratches seen here are more tangential. The brown spots could be related to old film, but, if you used fresh film, I would be concerned that your film had collected dust prior to development.
Where is development being done? A dedicated darkroom, bathroom, kitchen sink, laundry room? Is the film loaded in a commercial changing bag, home-made changing bag or darkened room?
Whatever your issues are are correctable. If it makes you feel any better, when I first started development at home, my first few rolls were perfect. Probably because I was somewhat OCD about the process, and did multiple dry runs before doing the actual processing. As I became more comfortable, I began having errors. Over time, I have learned which parts of the process are very important, and which are less important and have refined my processes so that I am comfortable, but not cavalier, about the process.