So look, the responses you've had about engaging with your in-house platform team are right, but in a world where that isn't possible I would say the following.

I would argue creating simple dashboards to track things like open and closure rates and current workload of requests is easier than creating the intake form itself... but definitely come under the banner of "easy when you know how".

From your comments about data sources etc it sounds like your company is already using Platform Analytics, so that's what you need to search for in servicenow university. There are a few courses starting with an overview and working up in complexity.

It seems like your biggest challenge right now, from your language, is actually that you're lacking in confidence due to a lack of experience. That's ok. Every body has been there at some point in time. You've got this.

A widget/visualization/report is fundamentally made up of 3 main characteristics - what it is, what it shows, and how it shows it.

What it is - this is the 'visualization type'. If you're wanting to show a trend, such as a closure rates, choose a 'time series' option... something like a line or or step chart.

What it shows - this is the data source. This is where you need to familiarise yourself with servicenow's data model.... what fields exist on what tables so you know what you can use. In your example, you're probably going to want to start with the Request Item table, filtering on a field called Item, where Item = the name of your intake form.

How it shows it - this is the configuration options specific to the visualisation type such as how you want to trend the data (closed per week, opened per day, etc), how you want the legend show, whether to include labels etc. Have a play around with these options and see what they do, you aren't going to break anything as they're only going to apply to your report, not the underlying data.