Hi, Eduardo,
Welcome to the forum!
To get a truly satisfactory answer to your question, I recommend consulting with an experienced guitar teacher. If you give them an account of your past musical experience and present knowledge, and a vision of where you want to go, you will form a clear plan of what to do now and what to save for later.
For now, I can say that the melodic minor and harmonic minor scales are compositional tools. They exist to create authentic cadences (V or vii dim —> I or i). You will encounter them in melodies where they are called for and likely not even notice them.
After consulting with my own instructors, I deferred Steve’s session on pentatonic scales to focus on the major scales. This is just one approach. I think Steve introduced pentatonics in the course where he does to give the student momentum in learning the fretboard, and pentatonics are a little simpler than major scales.
So much depends on what you want to do with guitar. That’s where a real conversation with a teacher is invaluable. I'm sure my friends here will offer good insights.
until