No, you don’t have to do any of that at all. You open up an account at a photo storage site, upload your photos, then embed the link to whichever image you want to show up in your post and you are done.
The procedure has been outlined many times here and on other sites. If you search the site you will find many examples of how to do it and what works the best.
You can embed images in the forum several ways but I like to just use the
code where xxxx= the url of your image from your image storage provider. That way the full size image just magically shows up in your post - no visible links or thumbnails to click on.
Like this
https://i.postimg.cc/qBsTqt2q/P1080980.jpg With the
in front and at the end of the link this is the result.