Hi is it possible to do this by using these steps:
1. Show button with text to say download with text underneath saying login or signup to download. This button is hidden when the “resources downloads” member is logged in and the actual download button with the attachment is showing.
2. If logged in as a certain admin e.g. named “resources downloads” and “administrator” it shows the download button with pdf attached.
3. If they have to signup first to download then the link pops up (modal) a register for the person to be “resources downloads” member only.
4. If they are registered as a “resources downloads” member then the link to login pops up (modal) to sign in to download.
5. When logged in the original button is hiding and only the download button is showing.
It seems very do-able, but I probably wouldn’t use ACF for it.
I’d start by getting the custom login form sorted (there’s lots of different ways to do it: https://bit.ly/2vZIMsJ) and then working on the other bits.
Let me know if you need any more info.