Follow the clues
Resident Evil 3 still has those classic safe code mini-puzzles, and one happens to occur very early on.
Although it won’t be the last safe you encounter over the course of the game, this one is arguably one of the most important as it gives you a leg up at the start.
Minor puzzle spoilers below
Your first stop is the pharmacist’s home, which you’ll encounter as part of the main story. Right before the diner (donut shop) you’ll have the opportunity to walk upstairs into a catwalk area: head to the left and into the apartment.
The note gives you the clue, but you may not get it at first. The pharmacist boasts how not even his wife knows the code, but his Aqua Cure Queen does. Go out the back of the apartment and down the catwalk.
Your next stop is the pharmacy, directly to the right at the end of the catwalk, street level.
Head in, turn left, and look right in front of you: the Aqua Cure Queen is an advertisement. Look closer underneath. It’s the code!
The code can be randomized, but this is an example of how it is displayed.
In the image above, note that the code translates to left 9, right 1, left 8.
Head back to the apartment and enter the code for a red dot sight for the pistol: it’ll make your life a whole lot easier when it comes to headshots after you combine it with your pistol in the inventory screen.
If the way back to the apartment is barred, go through the dinner, turn left and go back up the catwalk.