I don't understand how to read a tab chart, or what the numbers have to do with the strings. Is that the finger I place there or the fret. And how am I suppose to know how it sounds?
The numbers are the fret for the string. TAB's do not typically tell you what fingers to use.
Here is a good article/lesson on tabs https://www.guitarnoise.com/faq.php?id=136
What does it mean when it has the same number multiple times on the same string or different strings?
It means you play string once for every time the number appears.
Consider each number a note (except instead of showing a note like standard notation it shows what fret to play) and each line is a string (top line is high E or thinest string and bottom line is low E or thickest string)
Sometimes you will see more than one number in the same space (above each other) that means you play those strings at the same time.
Sadly most TABs will give you no real sense of rhythm so being familiar with the song or having a recording is almost a must when using TAB.
