If you are looking for datasets from amateur astrophotographers to practice with, there are a number for useful resources.
Processing is meant to be fun! If you really need help with a particular dataset, jump on the forums or contact us directly for some pointers - even if you're just using the trial.
Thank you StarTools for turning my average photos into amazing ones.
The Shrink module allows you to modify the appearance of stars in your image.
Once all issues are fixed, launch AutoDev again and tell it to 'redo' the stretch.
You can convert everything you see to a format you find convenient. Give it a try!