sample rates in Audacity
When you export a file from Audacity, it will have the same sample rate as the project settings.
To see the project sample rate, click the “Audio Setup” button, then the “Audio Settings” menu item in the menu that appears. There you can change the project sample rate.
Here's a page on the Audacity website about sample rates: https://manual.audacityteam.org/man/sample_rates.html
You'll notice that there's a “Resample” item in the “Tracks” menu, but this ISN'T what you want: https://manual.audacityteam.org/man/tracks_menu.html
48 kHz is totally fine for us, and probably 44.1 would be OK too. We'll choose 48 because it's high-quality. By being specific about sample rate, we're going to prevent problems. In some applications, having the wrong sample rate will affect the perceived pitch of sounds. 44.1 kHz played at 48 kHz will sound like it's been “sped up”, with the perceived pitches being too high.
Using low sample rates will cause the sound quality to be poor; they will lose some of the high-frequency information that would otherwise be present if they had been recorded at higher sample rates.
There's more to learn about sample rates and sample rate conversion, but for now you should know that while it's possible, if you raise a low sample rate to a higher one, it's not going to sound any better. Be sure to record at the correct sample rate.