I know this is a pretty basic question but does Sketch come with a set of standard shopping cart icons like change quantity? If so, where would I find it? If not, where would I find those kinds of resources? Thanks.
No, Sketch doesn’t. The best way to find icons like that is to search the internet for free icon sets. Often times these sets allow you to “copy” the svg code. If you do that you can paste cmd+v directly into Sketch and it’ll paste the icon. The other option is to download the icon form these sites and then place it into Sketch.
There are a lot of decent free icon sets. A nice website I found seems to be a collection of links to different free icon sets that you can try out: https://icones.js.org/
For some quick links to good icon sets you can also try out https://phosphoricons.com/, https://heroicons.com/, and I bet some other people have their own favorite icon websites.