I was thinking about start streaming, but my problem is that I don't no what video settings should I use.
My PC is quite good enough, so the problem stands for the internet connection.
Download: 12,5-13 Mbps
Upload: ~850 kbps
What bitrate, video quality, etc... should i use?
You have a very bad upload speed, I don't think you can stream well at all using that connection. Maybe at low quality 800x600 resolution.
And the Bitrate?
Would have to be lower than your upload speed, and keep in mind that other things will also be using that connection, so you probably would need to keep half of your upload speed free for them. Try 400kbps and see how it works.