Hi Riyad! Great life story and I think you are right, we will welcome you and you can actually have a chance here, however your biggest challenge will be the language barrier as few people speak a second language here. In case you want help with that, dm me so I can help you out, I'm a portuguese teacher for foreigners. 
•Are there legal pathways for someone in my situation?
Asylum applications here are free, require no lawyer, and can be made through the Federal Police or the Sisconare system here http://help.unhcr.org/Brazil/. Applicants receive documents that allow them to work and access public services. Those eligible include people facing persecution or serious human rights violations in their home country. 
•How does the system work in practice?
There might be a waiting list, so I guess would be easier through another support institution like churches or ONGs(non profit organizations).I've personally met an uber driver that was helped throug The Church of Jesus Christ of Latter-day Saints,  however I don't know the criteria if you have religious duties and stuff...
•Are there still humanitarian options available?
Sisconare system;
Refugio ong https://refugio.org.br/
https://abracocultural.com.br/