Adding target value to guage

Trying to add a simple target value to a guage. couple questions:

1. I am trying to create my own table that can include a metric name and values (of which I can use within other charts). When I hit "New table" I can get what I want but when I try to add more rows I can't find out where to do that after my initial creation

2. When I used this field from #1 in my target notihng shows up. It is just one row with a simple .75 as a value which I wanted to show between my beginning and end values on the guage (0 - 100%).

3. It seems like we always need a field to populate a data within in a chart/kpi, etc. Isn't there a way to just type a hard coded number into a value?

Thanks for any help - new to Power BI

Steve