[lecrae]

Is there anyways to drag and drop photos onto my iPhone? I've never actually used the photos app on the mac before and am very confused.

[Jeroen7]

If you use icloud photos it syncs automatically!

You cant reallu use the iPhone as a usb harddrive if thats what you mean.you can however airdrop photos to your iphone to save them, or use dropbox and then save the images on your phone.
But I think icloud photos is just the easiest way.

[BlackNightmare]

Apart from the above mentioned solutions, there's also an alternative way: you can sync photos you put in a folder through iTunes, though the dedicated section in the syncing panel. Even if you can in this way store photos on your iPhone from the PC, note that you won't be able to delete them directly from the phone (you have to delete the pic on the PC folder and then sync).
Also, I'm not sure if the actual panel is present/functional in case you are using iCloud Photo Library

[pkcable]

If you use icloud photos it syncs automatically!

You cant reallu use the iPhone as a usb harddrive if thats what you mean.you can however airdrop photos to your iphone to save them, or use dropbox and then save the images on your phone.
But I think icloud photos is just the easiest way.

Apart from the above mentioned solutions, there's also an alternative way: you can sync photos you put in a folder through iTunes, though the dedicated section in the syncing panel. Even if you can in this way store photos on your iPhone from the PC, note that you won't be able to delete them directly from the phone (you have to delete the pic on the PC folder and then sync).
Also, I'm not sure if the actual panel is present/functional in case you are using iCloud Photo Library

Combining for best answer

[lecrae]

I'll definitely try both! Thanks for the help