ssd update für macbook pro

Get an external SSD (or regular) hard drive and move all of your space hogging files (videos, photos, etc) to the external drive. You need to maintain a minimum of 10 - 15 GB of empty space at all times (in the case of the Catalina installer you actually needed more because, in addition to the 8+ GB installer, it needed 20 GB to expand and install).

You cannot. The 2017 MBP cannot be upgraded.