Postimage is free.
https://postimages.org/.
I have some images up there, haven't posted pictures in a while but let's give it a try.
Uploading as I recall is not as difficult as getting a picture to the forum.
Once the image is uploaded, select "share" and then copy the url next to "Thumbnail for forums:". On the right click on the copy icon.
Paste here.
As we can see, that worked. There are others that are better at this. Knotty is really good.
One thing that might help. You are not copying and pasting a photo, but the link to the photo. So, that is what you copy and paste, a link, and that is what you will see. Then after you submit the post and go back in to your post you will see the photo.
This should get you started. If you have any problems let us know. Looking forward to your photo(s).