I'd like to suggest you check out some basic tutorials on youtube. I think you would really benefit from following a few. Everyone has to start somewhere!

Anyway, this isn't a tutorial, but hopefully there's enough information below to get you started.

1. Select an object

2. Open the Fill and Stroke dialog

3. Select the Stroke Paint tab

4. Choose the "Flat colour" square. This adds a stroke to the path.

5. If nothing shows up, the stroke is probably just too thin to be seen. If so, click on the Stroke Style tab, and increase the stroke width

6. In the Stroke Paint tab, choose a colour

Note you can change other stroke styles in the Stroke Style tab.

Example showing changing the fill, stroke paint, and stroke style.

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/Mtm3h.gif