Hi,
I would strongly recommend that you do the embedded tutorials in the Fusion Documentation and also some of the
Self-Paced Learning to help you to learn fusion faster and better. They can be found here:

It is also much easier for the forum to help you if you attach your file AND a screenshot of what you want to achieve
and what the problem is. You can create a file to export like this:

There are a number of different ways to make this shape. A very common way to attempt this would be to use
extrusion or combine cuts.


Basically what you do is create smaller simpler shapes and use them to literally cut out pieces of material until you get
what you want.
This shape I began with a simple rectangle and extruded it then used the shell command to hollow it out. I then
rounded the corners with fillets and used the chamfer command for the sloped sides.

You then need to draw another sketch using the "floor" of the shape as your plane and do an extrude cut like this.

Then fillet the edges of that cut.

Now while what I have done is far from perfect, it is close to what you want and it took less than five minutes to knock
up. It helps a great deal if you have the actual measurements and you can get it a bit more exact.
Cheers
Andrew