Question about Space

Does anybody know how to figure out the distances between stars that aren't the Sun? Like, I want to know the distance between, say, Barnard's Star and HIP 76976 (aka the Methuselah Star). Actually, what I'd like to be able to do is create one of those distance charts like you see in a road atlas, showing how far it is to drive from Chicago to Albequerque or New York to Miami, that kind of thing.

I've found some information online, including a couple of calculators and I've got enough information to begin making some speculative ideas for some worldbuilding I'm doing, but I'd like a nice, easy to read and expandable spreadsheet. I found some sources that give a mathematical formula for doing it but I cannot make my data come out right (this might be a user-interface problem because this is spherical trigonometry and I barely passed college algebra).

I'm specifically looking for stars that are within 190 light-years of Earth because I'm trying to create an interstellar empire of sorts. If you can explain the math to me, please put it in the most basic terms possible. Like, explain it to me like I'm five kinda thing.

These are my sources:

http://fmwriters.com/Visionback/Issue14/wbputtingstars.htm

https://worldbuilding.stackexchange.com/questions/148584/how-can-i-measure-the-distance-between-two-stars#:~:text=The%20unit%20for%20the%20distance,the%20angle%20between%20the%20stars.

http://www.neoprogrammics.com/stars/distance_between_two_stars/index.php

https://www.wolframalpha.com/widgets/view.jsp?id=1ece06643e87f3c4d90813af5ee12223

ALSO: I'd like a reliable source for the ages of various stars because I need stars that are at least as old as the Sun, but preferably older.