As I learned in this question, the cog of my freewheel are damaged and should be replaced.
I've been searching for some information but I'm still not sure of what I need. At the beginning I though I just needed to search for a cog like this with 1/8" like my chain:
But reading the description it seems like it's only for fixed gears, so I was completely worng. Searching for more items under the single speed category in the website everything looked like that.
What do I need to buy as replacement?
As tools a I just have the basics, when i search for freewheel remover I see hundreds of different things like this:
...
How can I know what I need?