I was an unpleasant teenager. I am not proud to say that I regularly made homophobic and racist jokes and comments throughout my adolescence, although - this isn’t an excuse so much as an addendum - I’m not sure how much I ever really believed it deep down. Did I honestly think that white people were genetically superior, or that gay people were morally repugnant? Truthfully, I don’t think I even ever gave it that much thought; my behaviour was mostly just a crude imitation of what my peers were saying.
Up to my early 20s, I still used “gay”, “faggy”, etc. as generic pejorative adjectives - “ugh, that’s so gay!”, again really without much thought as to the implications of how I was using language (if you use “gay” to describe something negatively, you are pretty explicitly indicating that you think being gay is undesirable - or at least very much giving that impression). It took me longer than I care to admit to realise that.
Coming back to the OP, though, I am highly unlikely to ever be judged by such behaviour because a) I grew up in a time before social media and ubiquitous mobile phones, and b) I’m not important enough for anyone to care. Indeed, there are only a handful of photos of me during that time (and, I believe, no videos at all) - and certainly no textual records of things that I said or did. This is just as well.
Young people now do not have the luxury of what they say and do being forgotten and unrecorded. To an extent, this will require that they moderate their behaviour more than their predecessors (I read somewhere that the latest batch of young people are the best and most modestly-behaved in recent history - that might be why, although should probably find a cite for that). But those in more mature generations also owe a certain degree of forgiveness to those who are relatively new to life; holding a 30-something to account (say) for something they tweeted when they were 15 is simply unfair.