When I try to assemble some code, I get

bash: fasm: command not found

What am I doing wrong ?

Thanks.

I forgot to use ./fasm.

Can I create programs in a gui like format ?

I did not see any source examples.

You can use GTK, for example.
gtk-examples.tar.gz

There are several in Fresh IDE package.

Try putting the directory FASM resides in into your path, or just move it to a dir already in your path, like /bin or /usr/bin. Then you don't have to ./fasm, you can just fasm from anywhere.

This is what I did, since I use the built-in 'compile' feature on Emacs a lot. Then Emacs will just use 'fasm' instead of '/this/is/a/long/path/fasm'.