You'll need to create a new document with the background type set to transparent. Then copy/paste your logo into the new transparent document as a new layer. Then select the white area around your logo and delete it (looks like you can probably get away with the magic selection tool here).
Just as a heads up, most logo is done using vector-based software, like Illustrator, so that it can scale. It's going to be hard to keep the logo size consistent relative to your images if you crop them at all.
Don't be discouraged by any of that, you've got to start somewhere and you've done very well so far! Your logo is much better than some I've seen!
No one learns all of this stuff overnight... I've been using Photoshop as a hobby since version 4 came out ~15 years ago, and I still don't know all there is to know about it. Just be patient, and have fun! 