Hi, Cranberry.
You might want to pick up a book on sight singing and ear training. One that was recommended to me has that name, Fundamentals of Sight Singing and Ear Training, by Arnold Fish and Norman Lloyd. I have the book, though I haven’t used it much. If I get a chance to pursue my music reading, I believe it will be very useful.
Any book designed to help with learning to read music will have a lot of simple exercises for learning to dicipher rhythmic notation, as well as pitch notation.
Another suggestion is something I learned from my brief time singing in a choir.
I can often pick out a tune if it’s not in an odd mode or something, by trying to figure out the root note and the starting note. I can usually tell by the sound of the melody if it’s a major or minor key. From there, I try to figure out what’s the “home” note, usually the note the tune comes “home” to at the end. Then I compare the home note to the starting note and try to figure out what interval it is. Does it start on the home note, or something higher than the home note?
If it starts on the next note up the scale from the home note, I can tell pretty easily.
If it starts a minor third up from the home note, the interval will sound like the first two tones of “Greensleeves.”
If it starts a major third up from the home note, the interval will sound like the first two tones of a 1351531 arpeggio.
If it starts a fourth up from the home note, the interval will sound like the first two tones of “Here Comes the Bride.”
If it starts a fifth up from the home note, the interval will sound like the first two tones of “Twinkle Twinkle Little Star.”
If it starts a sixth up from the home note, the interval will sound like the first two tones of the “NBC” signature triad.
If I can figure out the first home note and the starting note of a tune I have in my head, I can usually work the tune out on a whistle pretty easily from there.
I’m sure others can add more to this, too.
Best wishes,
Jerry