If both fuses are blown then check to see if you have a short on those circuits.
If fuse is good, then check the relay for the horn.
If relay is good, then you might have a loose ground.
If you do not have a multimeter then get one. If you do not know how to use one, then watch a YouTube video on how to use one. They are rather easy to use and are a very valuable tool to have in general. Innova is good for automotive and Fluke is always a good bet. If you are tight on money some RadioShack meters are made by Fluke.
It could also be that your horn and outlet are bad, connections are undone, or just dirty.
Troubleshooting electrical can seem difficult, but it's really not bad.