I`m new to analogue photography, and therefore don't know why there're streaks in different colors on my film scans or why some are in completely different colors. I got it developed and scanned in a professional shop, so it probably wasn't a mistake in the developing process. And it's not on all the photos of the roll, many turned out perfectly fine. Hope someone can help me. Thanks!
Those colors are caused by the film being exposed to light leaks occurring before exposure (faulty cartridge), in your camera (back not closed, faulty shutter, back accidentally opened), or during processing (careless handling).
If these are at the beginning of the roll, it is probably due to a leak in the cartridge or not doing two or three 'loading' exposures to get unexposed film out of the cartridge and ready to go. Your film counter should tell you when you've advanced to the first exposure.