Are you really trying to read musical notation? That’s something that you certainly can do, but I wouldn’t recommend it as a starting place at all. If you could fill out your profile by clicking on My Account at the top of the page, that would give us all an idea what your experience level is, type gear you have, etc…

To practice reading notes on the treble clef, I use the following site:
https://www.notationtraining.com/treble-clef-practice

The notes that fall on the lines starting from the bottom are E, G, B, D, F. I learned it with the acronym of Every Good Boy Does Fine Always. Then the spaces are F, A, C, E. The more time you spend practicing at it the better you get at reading notes. The treble clef itself is a fancy way to draw the letter G, and if you look closely the way it curls around the line that is second from the bottom on the staff. That’s the G line!

Here is an example from the above site:

The center line on the staff is a B (major 7) note, the next note is down one major second (two frets), so it has to be an A (major 6th) note, the next note is a major 3rd interval down (4 frets), so that is an F (major 4th) note. Now the intervals are getting wider as it jumps up to B which is the major 7 note in C major scale. The next note is an octave jump to another major 7th B note. Back down to the 4th F note (at first fret on high E string). Then it drops down to E (2nd fret on 4th string) which is the major 3rd. Then back to the same F as before.

I injected an association of the scale degrees onto the notes in the C major scale. This is really good to be aware of when playing any kind of music.

You can also practice the bass clef there as well. I would not put a ton of effort into it if you are trying to learn guitar though. It’s great to know, but certainly way down on the priority list of things to learn. I assume you have some books that do not have tablature in them. I would file those books away and get books that have tablature in them. I have some of those books as well and I wanted to learn for the very same reason, but it’s not a good use of your time IMO. I don’t regret learning to read music, it’s just better suited for other things like classical guitar. You pretty much have to learn to read music if you are going to play classical guitar.