How to send designs to a client?

Hi all! I'm a student graphic designer and I've just finished working on my first branding job for a client, but I'm slightly lost on what needs to be sent over and how? I've had a look online and some places are saying to send just SVG, ESP and PNG files, wheras others are saying to send AI, PDF and JPGs too? I'm also wondering how people normally send it over? Is it best to structure it on something like dropbox and then send over the folder or is there a better way? I'm also wondering if I should include a brandbook in the folder explaining it all or if I should just drop her a message when I send the link to the folder over?

I'd appreciate any and all help you can give me! TYIA!