Congrats! Really nice looking star note. No folds that so can see, looks crisp and no stains. Only worth face value but I'd keep because it's your first one.
The letters in the serial number are supposed to match. They indicate the district they came from. In this case, San Francisco.
These two links explain a lot about paper bills and the meaning of things on the bills. Look at the reverse of the bill. Look under the pyramid. There are a number of Roman numerals. The date is 1776, the year of our Independence. The top of the pyramid is separated and has the All Seeing Eye in it. Hopefully these links will answer your questions. https://www.moneyfactory.gov/resources/serialnumbers.html http://www.uspapermoney.info/general/number.html
Yes, just because both letters are the same is meaningless. Read the moneyfactory.gov link. Look up serial numbers. It explains what you are asking better than I can. All I. The first 2 paragraphs explain the letters meaning. This will help you understand but it does not answer your question. The money factory link does.
That's grea Joy! I'd save all of them. No real reason other, just because. Because I can, because I found them, just because I want to. I have about $400.00 in Star notes in ones, twos, fives and tens. Over $1,000 if I add in the other denominations. Why? Because it's mine.
Right my guy even told me my Erie Pennsylvania bank note is rare and hard to come by so hold on to it and my 3 consecutive note will be worth more later on so so what if I'm a hoarder one day I won't be.