As for posting a picture, use the "Attach files" link at the bottom left of the message box. Click on the link, find your way to the photo file, select and import it, and select either "Thumbnail" or "Full Image." This forum makes it easy to insert photos inline (within the body of the post).
You will find several threads on inserting and editing photos here:
Welcome @ChuckF33 as others have said above attach files and then you can insert them inline as thumbnails or full size as desired. I suggest playing in the test forum and get to know the forum'ware, it's super easy. Yes, you can use Tapatalk if you want or you can view this site directly in your mobile browser as no app is required.