Strings buzzing can either be the action being set too low, or the frets needing dressing or the neck not having enough relief or being actually warped. We can't tell from here.
https://acousticlife.tv/fix-your-acoustic-guitar-buzz/
https://acousticguitar.com/ask-the-expert-why-is-my-guitar-buzzing/
Learn how to adjust the truss rod in your guitar, if you can. That's the easiest fix that does not involve specialized tools, filing frets, or disassembly. You may need to buy or borrow a long hex driver to reach the truss rod adjusting nut
https://www.youtube.com/watch?v=xyqrSRI2asc&feature=youtu.be&list=UUM-CsUeK57J8grv9BSBRRhQ
If it is a simple relief problem, that may fix it.
Adjusting the height of the bridge requires taking out the bridge and shimming it, which involves some woodworking skills (unlike an electric guitar where you can adjust bridge height and intonation with screwdrivers and or hex wrenches)
https://www.haloguitars.com/store/blog/what-causes-fret-buzz-and-how-to-fix-it/
https://breedlovemusic.com/acoustic-guitar-blog/how-to-fix-and-avoid-fret-string-buzz-on-a-acoustic-guitar
This should be possible to fix, depending on the cause, but because this is an acoustic guitar adjusting the action, frets and any major neck issues is a job that should be looked at by a qualified person. Keep in mind that your Alvarez is not a hugely valuable guitar, so you want to set a budget and get an estimate.