fender custom shop guitar

Help with Ernie Ball string sizes and a Fender Strat, please?
I’ve never had to buy new strings for my electric guitar until today, and the strings that the girl in the shop gave me seem to be either too thick or too thin.
The guitar I have is a Fender Strat and the strings she gave me are “Ernie Ball, Regular Slinky, Custom Gauge”.
I want to replace the A string on my guitar, so which number string should I use – 10, 13,17, 26, 36, 46?
And if you think a different brand of string would be better for a Fender Strat, please give me some suggestions!
Thanks
The 36 gauge is the A string. However, if your changing brands and gauge, I’d replace the whole set. That set is on the light side, but not overly so. Ernie Ball Slinky are good guitar strings, but everyone who plays guitar has their own opinion on what the best string is. I prefer D’ Addario, some prefer Elixer. Your best bet is to try different sets until you find one you like, that works with what, and how you play.
Fender Custom Shop Roadshow part 3 @ The Music Zoo