@Foxley828 Click Windows key-shift-S, then drag your cursor over the section of screen you want to capture. The screenshot will show up in a notification in the lower-right corner of your screen. Click on this, and you can edit it and save it to your desktop (or wherever you want) from there.
For the Tray folder, click the date modified header, which you can only see in detail mode, so that the newest files are listed first. You might have to click twice to organize it this way. Then just post a screenshot of those newest items.
To post the screenshot itself, click Reply (not Quick Reply), then click the Browse button below the text field and next to the paper clip icon, and select your screenshot. Repeat as necessary. Alternately, you can click the Insert Image button above the text field; it's two to the right of the emoji button.