Executive Summary: whether your "storage disk" will have the data you want will depend on what it is, how the data were transferred to it and what app the notes were stored by. If it does contain the data you want, whether you'll be able to read them without another phone (i.e. the same app that wrote them) will depend on what app the notes were stored by.
So, firstly, which app did you use to create these notes/memos? I'm going to guess it's Samsung's built-in notes app (S-Notes?), but it's better to know for sure than to make assumptions. Because if you can find the data which app they come from will determine how/whether you can read them.
Secondly, how did these data from the phone get onto this "storage disk"? Because how you copied the data there will make a difference to what is saved, e.g. copying the visible part of your internal storage over USB will save different things from using some Samsung backup utility, and both will be different from just removing a microSD card that was being used in the phone.
But assuming it's S-Notes that you used, look for a folder in there with a name like "SnoteData" (or anything that implies S-Notes). That's how Samsung store such things in the visible part of the internal storage on my ancient Samsung tablet, which is the only Samsung device I have (and, full disclosure, I don't use S-Notes so won't be able to help much if that is what you were using). By default they do not store them on the removable SD card (at least on my device), so if that's what you have then by all means look but don't be surprised if they aren't there. As for reading the data, they probably aren't in a format that anything other than Samsung software can read, and I don't use Samsung software so can't tell you whether for example Smart Switch on a computer can read SnoteData copied on there - unless someone else has an answer all I can say is "try it if you find the data".
If the notes were stored by another app it will depend on where it stores them and in what format.
The first rule with important data: always have a backup that you can access without the device you normally use. Sadly you are now discovering why.
Good luck.