Walaykum Asalam wa Rahmat Allah Wabaraktuhu,
Jazak Allahu khairan and May Allah accept your sincerity and your efforts to rectify any wrong.

The issue is we do not want people to live in misery or heartache, or any sort of damage because of something that we have done. The Prophet (ﷺ) said, “No one of you becomes a true believer until he likes for his brother what he likes for himself.”[Al-Bukhari and Muslim].

We certainly won’t like it if someone hurt us or damaged us in anyway, and then they went about their lives as if nothing happened.

So, the point here is for us to have a heart and mind that are awake and compassionate and full of mercy and justice that we don’t simply harm others carelessly.

To answer the question, what one could do is:
1- Make sincere dua to Allah to enable you to mend the wrong and sincerely apologize to others and bring them their right back.
2- Make dua to Allah to bless those people and shower them with His Generosity and heal their hearts and heal them from any damage or wrong you have caused.
3- You can start speaking well about those people in the same places and with the same crowds where you’ve wronged them before (if that’s the case).
4- You can make a Facebook post for example saying you’ve hurt people before out of heedlessness or lack of awareness and that you sincerely apologize to each one of them wherever they may be and you make dua to them and wish they are in the best of states and wish they forgive you.
5- If there is someone in specific you remember and you can still approach them somehow, then at least fix it with that person. You can send apology note with someone else if you are unable to do it directly, you can send a gift…etc, there are many ways, ask Allah for inspiration, and He will open doors. (Please see more tips in the reply for Br. Yaqoob above in the comments section)

And of course, we do all of that bearing in mind we take the halal means and that we don’t fix the wrong by doing more wrong like approaching a non-mahram exclusively or privately for example…etc.

So basically take the means within what’s reasonable and what’s available for you. If there is nothing you can do and it’s absolutely impossible to reach someone…etc., then just make heartfelt dua for them. And may this issue humble your heart and make it more awake and conscious, and help you be a good and inspirational example for everyone around you in the present and future insha’Allah.

And Jazakum Allahu Kairan. And May He reward you too. Ameen.

Ameen to this very precious dua and may Allah shower you with His Generosity and accept your deeds and beautiful sincere intention. Wa Jazakum Allahu khairan, Sister.

AlhamduliAllah for this! It’s the Mercy of Allah. May Allah continue to bring us what benefits us, and help us act on it. Ameen.