Start with BiggerPockets Ultimate Beginners Guide (free).

Juan,CU can be tough when it comes to guide lines, overlays, DTI, credit, property type/condition. 

California has a lot of regulatory compliance and recommend a compliance attorney to guide you. 5.

They can verify your eligibility for the VA IRRRL and guide you through the process without the risk of dealing with potential scams.If you have more questions or need further assistance, feel free to ask.

@Agustin Silveyra have you looked into finding a house hacking agent yet to guide you?

Let me know how I can help to guide you.

Use them as guides in decision making not hard and fat rules.

I started with some youtube videos, as well as reading BiggerPockets Ultimate Beginners Guide.

This is a great forum with very knowledgeable members that will help to guide you in the right direction.There are some pretty cool discounts on various products and services offered as Perks to BP members that you might want to check out: https://www.biggerpockets.com/perks/pro

As a foreigner getting conventional lending might be an obstacle and I think there will be many people on this forum that can provide resources to guide you through.