Java Script or HTML5
I'd like to gain further understanding of the different codes issued out by Analytics & Tag Manager in order to reduce the number of issues on my web pages as I am launching a new company. I am not intending to become a master at code, but I do need to spot simple mistakes like the ones I have had on my pages.
Which codes are being used by GA and GTM and which should I invest time in learning, HTML5 or Java script or both?
Thanks In advance!