As a threat intelligence engineer you need some form of education. Mostly bachelors. Threat intel can be broken into so many areas but a good experience with SQL, Python, Research(I mean going out there to look for TA and TTP) and SIEM or EDR tools would come a long way. Remember guys you dont need a degree but keep in mind you are going up agains people with masters or bachelors in computer science and months of internships. I can't tell you how to even the playing ground but just keep that in mind