I don't know about you, but personally, I have managed to go my entire life not knowing a single question one might be asked in an exam to get their medical license. I have never read a pilot's manual. I've never participated in a fitness test to join the Royal Marines. These are just three examples of very specific areas of knowledge and skill I have never needed. Why? Because they are simply not applicable to me. Doctors, pilots, and marines are all in very niche careers that require very niche skill sets.
Is Christianity a niche religion? Certainly not. While not all people are supposed to become doctors, all people are supposed to become Christians. Even children. Therefore, it is self evident that the Christian faith is accessible to all people.
It makes no sense to give a medical exam paper to a teenager, but according to Scripture itself, the word of God "gives understanding to the simple" (Psalm 119:130). By meditating on it day and night, even the simple can become as expert on it as their enemies, their teachers, and the ancients (Psalm 119:97-100).
There are many today, particularly heretics, who will insist that you cannot study Scripture on your own. You must learn other things, and conveniently, it is the things they have to teach you. But in truth, if you want to study Scripture alone, the only qualification you need is the ability to read. If you can read, the Bible itself tells you to study it. Just as a degree is not a certificate of infallibility by God, it is also not a requirement to understand or participate in the Christian faith. Woe betide the arrogant Pharisee who tells you only they can teach you the word of God.