Planning on moving from Romania to Spain. (advice needed)

Hello, everyone!

I'm Romanian, 26 years old, and thinking seriously about moving to Spain, probably within a year or so.
I currently am employed, been working for 2 years now(energy industry).
I am quite familiar with Spain, as I've visited and traveled throughout the country plenty of times on different occasions. I also have a couple of friends that are Spanish and a relative that has lived there for just over a decade.

My main reason for moving is because I want a change of lifestyle.
I want to move to Spain, because I love the country, people, and the Spanish general way of life. I like pretty much everything as a whole. Everything there seems to fit me perfectly.

I'd prefer to live in Madrid, but I'm open to other options if needed. Some of the other cities I really liked were Leon, Zaragoza, Valladolid, and quite a few more.

My main hobbies are riding motorcycles and guitar/music. Here's why I said I'd live in Madrid.  I've been playing guitar in local bands, mostly metal, and Madrid is by far the most "fruitful" place where I can pursue my passion, find like-minded people, form a band from scratch, or join one in need of a guitar player.

My question is:
What are my chances of landing a somewhat decent job, as a foreigner in Spain?

This is my biggest concern. By decent, I mean a job which will allow me to be self sufficient.(affording rent, paying bills and going out)

I've heard English teachers are in demand, but that's just not for me.

I do have a bachelor's in cartography and master's degree in natural gas engineering.  I don't necessarily want to work in the same fields as the ones mentioned above. I'm open to other unrelated fields, if any given company(not in the aforementioned fields) would employ me.

I speak Romanian and English.
Already speaking some very basic Spanish, currently studying hard.

I'd already look for job offers, see what's available and what not.  Also, what are my chances of landing a job at a company outside of my field of studies? Where should I start looking for job offers on the web?

Thank you in advance.