@AngelaBlue, I’m going to disagree with the person you are replying to. They can’t accurately guess effort here.
I would also advise not to skip this advice and simply ask your dev team to copy/paste the installation script as these tools frequently suggest. Worst-case scenario, you will be getting a bunch of invalid and hard-to-interpret data, like a bunch of sessions that appear to only have one page view to your homepage and 100% bounce rate because Google couldn’t pick up on new history states of your application.
Lastly, Google Analytics does not give you a single view of any one customer, so drawing meaningful conclusions about user behavior takes a lot of guess-work and requires you to start first with a hypothesis and then try to figure out how many sessions met that criteria. Mixpanel is better in this regard since they do let you narrow in to the individual and find unpredictable behavior among each (like navigating back-and-forth between reports,etc.)
Tools like Heap, Fullstory, and Logrocket do autotracking, which means they automatically track everything they can about the state of the page the user was on every time they clicked or meaningfully interacted with something on your site. The downside (per the above article) is that everything is getting sent to a third party, so you need to make sure data that shouldn’t get tracked to a third party is explicitly excluded. It’s also a bit obscure to try to model all of the clickstream data they capture from their tool into meaningful metrics for long-term reporting, and they may not actually retain data very long because they capture so much. Your rules can also break as soon as your developers change something about the front-end that you were relying on staying the same. For instance, you can set up a metric that counts how many people clicked a button with the inner text “Log in” or how many people clicked a link with the HTML class “download-report”, but if those attributes change on your site later, those rules will break.
The upside is you can learn a TON about your customers if you are willing to spend time with the tool and you don’t need a significant developer resource to install them since they do a lot out-of-the-box.
If the question is “how do I know what users are using on my application” I frequently advise something that looks like this:
Install an auto-tracker with session recording built-in, like fullstory or Logrocket
Check in on day 2 to make sure it installed OK, but then let it collect some data for a few days
Come back and spend a day observing user sessions. Take lots of notes - what is remarkable and noteworthy about each session? What surprised you? Which behaviors would you like to measure over time, and do you want to know that per-page, per-session, or per-user?
Build your tracking requirements off of this - you’ll probably find a lot of events and application states you didn’t think of
Install something like Mixpanel or GA off of those requirements so you can reliably track those data points and events over time, and use those tools for your trend analysis, cohort analysis, acquisition and attribution analysis, etc.
Check in on your session recording tools a few weeks before you plan your next release so you know there aren’t any new surprises, and monitor them for hypercare after any higher-risk release.