You can absolutely blame the school system, as well as generational trauma and society in general for causing you to FEEL guilt and shame and for not teaching you critical thinking skills at an early age, which would make things a whole hell lf a lot easier on you. Hell, hamstringing schools and teachers to create a largely uneducated voter base which also mostly lacks the ability to think critically and challenge authority was a primary goal for the right since *at least* the 40s. And they got it!
But you cannot *hide behind that* as a shield to prevent you from having to do the unpleasant, scary thing and admit you don't know a whole lot, and then go and seek out the world. 'I don't know' is not an admission of stupidity!! Ignorance, maybe, but even then it's not a bad thing!
And I'll be the first to say that it is so, so hard to unlearn the shame of being physically punished for saying 'I don't know' or being told there's no such thing as a stupid question, and then socially crucified in front of the whole class when you ask the teacher something and they respond with some variation of 'Were you not paying attention?!' I have ADHD. Focusing in a classroom setting is nearly impossible for me. But I got called stupid anyway, by my peers, teachers, and even my parents.
Ask questions. But more importantly, make yourself comfortable with the phrase 'I don't know' as well as it's cousin 'I'm not sure.' Anyone worth their salt will not think poorly of you.
I would usually say the internet is a good place to start if you want to learn about things, but with search engines using algorithms that sort by popularity and profitability, I can't even say 'Look things up on Wikipedia and then scroll down and click through the references used for the article' because articles are paywalled because fuckin colleges (not the authors, usually) want people to have to pay for knowledge, which should be free.
My best advice is to ingrain into yourself that change is not bad. Changing your views and opinions and even the facts you believe in does not make you 'wishy washy' or 'flaky' or anything, it means you've recognized that our understanding of the world constantly changes. Facts are not immutable. Also, it helps to familiarize yourself with the actual meanings of words like 'hypothesis' and 'theory'. Not even experts have all the facts! It's ok to Not Know Things!! It means you have room to expand and grow and learn! It's a hard, long process, but YOU have to take he first few big, scary steps!
I would also like to add: even experts get tripped up on fiddly details. They cannot remember everything about their field of expertise off the top of their head if they're put on the spot with no preparation. They will flub things. The mark of a good scientist and usually a good person, is that they will roll with the stumble and often add 'i think its THIS, but it might be this, i cant remember right now" or something to that effect. Aim to be that person!