I think looking into the cognitive functions is the best thing. And I'm glad you feel comfortable typing yourself as INTP.
Have you looked at Personality Hacker at all? They use the MBTI typology within their own framework which they call the "car model". It helped me, and they have a lot of info out there. Here is a link if you are interested:
https://personalityhacker.com/personality-development-tools-the-car-diagram/ and knowing the cognitive functions of your type will be a big help when reading this.
Overall, I just want to say that since you are young, you may find it difficult to type yourself because you may not have enough life experience yet to resonate with some of the descriptions. And not every statement has to fit, just try to identify the type with the best fit. You are just in the beginning of figuring yourself out (I'm still learning about myself in my 30's and I just discovered this stuff) over the next 5, 10, even 15 years your sense of self dhould improve and you may find that certain descriptions do fit that didn't before. And I think you'll have a leg up since you are exploring this now.
My main point is this: don't think of typing yourself as the end goal, think of it as the starting point: a way to understand how you're wired, and don't be afraid to use it to explore and grow into the best version of yourself. That's how I see it anyway. Good Luck!