Madrid have become the number one City in terms of income and investors since for the last 25 years investor friendly goverments in the region had atracted the bigger companies of the world to invest in the city.

I'm      particularly interested in exploring the BRRRR strategy, despite the initially lower monthly cash flow.Long-Term Goal:- The ultimate objective is to achieve a monthly income of $15K+ through real estate investing within the next 10~15 years.I greatly appreciate any guidance, tips, or perspectives you can share based on your experience.

Income tax: A foreign investor receiving rental income from U.S. real property must pay income tax.

Or, your sellers could consider syndicated deals put together by reputable real estate investment firms that would allow the sellers access to income-producing assets that are professionally managed.  

I used to think that Section 8 was guaranteed income for Landlords, I neglected to think about the Loafers who still refuse to pay their half or percent, thanks for the lesson!

Do you have another income source right now?

So wanted to know is there any way or tips if you have, to assume Loan (may be VA loan) when my debt to income ratio is high?

The investment costs would be $300-$400k, with a potential profit margin of 60-90%, and a gross income on rents.

A lot of sellers are burned-out landlords who like the idea of "passive income"/mailbox money after years of chasing late rent payments, dealing with tenant BS and maintaining the property (I use quotes for "passive income" b/c no income is truly passive IMO, a wise seller will still pay attention to what's happening with the property in case they need to take it back, but collecting payments like a bank is generally easier than collecting them like a landlord, you can set up ACH with the buyer's bank or hire a loan processing company to handle it). 

They will look to work with small operating companies to get sba loans, but they will want to see two years of income : tax returnsSo if the company is a general contractor then its income / expenses could get it some sba loan but if you are fixing and flipping and are looking to get a mortgage they will look at you not the LLC