A very kind member on astrobin is making a load of his raw data available to anyone who wants it. It is released under Creative Commons license so all you have to do is give attribution if/when you show your final image. He is providing all the raw data, lights and calibration masters so you can practice pre and post processing.
if you want to get your hands on some very good data take a look here.
https://erellaz.com/moana/open-datasets/
I've downloaded and tried a couple so far and the data is very nice. Dont be put off by the images he shows beside the data sets - the data is better than that would suggest. For example this is the
This is what I managed to produce with that data
Which I think is pretty cool
And heres the attribution;
Data captured by “Moana Project” and processed by David Mackie
If its cloudy and your own data well is dry, check it out.