There are several ways you can format code here. You can highlight your code, then use the
</> button in the editor window, or you can place three backticks ``` (top left key on US/UK keyboards) on a line above your code, and three on a line below your code. I find this approach easier, but unfortunately some European and other keyboards don't have that character.
For inline code, a single backtick before and after does the trick.
There's a thread here (linked from the FAQs, if you need to find it again in future) which might be useful to you: