Adding my welcomes and that the black particles are just probably part of the natural process of cotton production and nothing to worry about.
Many of us have some difficulties adding photos here, but we do love them! If you haven't already, check out our help page, photo stuff is stickied to the top.
https://www.quiltingboard.com/qb-help-center-f27/
For me, the combination of a older digital camera with limited options/software and not a phone means my file sizes are too large and must be compressed. I go to this site here, no affiliation other than it is quick, easy, and does not set of my virus scanners:
https://www.reduceimages.com/
I drag the picture there, use their defaults and click once to reduce, and once to upload there, and then I come here, make my pounce and download. When you get to the screen where you have selected the photos, the other big trip up is that it is shaped wrong (to the old board format). You need to stretch out the window long and to the right to click the actual button.