Assalammu Alaikum Sister.
First, be aware Allah judges everyone by the following things-
-Knowledge
-Sincerity
-Action
In the first instance, I am presuming you were not aware of (at least not fully) of the exact nature of the importance of Salah in the eyes of Allah and how it should not be seen as a light matter by anyone. If that was true, then Allah will not hold you to account for what you did not know. This is because you now know of what Salah entails, how significant it is and what it means to delay or miss a single prayer intentionally and what the punishments are, both in this world and the next.
As long as you have repented, pray with dedication, pray all the Salahs as they should be and on time, you should be aware you have nothing to fear of all prayers lost and not prayed before now. Allah will not be angry with you and instead will be very happy to boast of you to the angels of your turnaround and how you have changed for the better.
Second, in respect to sincerity, Allah knows you your heart, how you feel, what fears you have of the Salahs not prayed, how you would have liked to have prayed them and all regrets is seen as a demonstration of your high Eman and your longing to be close to Him and your yearning to please Allah. As long as you remain sincere, all lost Salahs are wiped from your account and is forgotten or erased as a crime. This is as long as you do not return to not praying ever again. Only then will they be held against you on the Day of Judgement.
Third, what actions or steps have you taken since knowledge has come to you. This is not just restricted to what you are doing for yourself (although even this is acceptable on its own).
That is, praying all Salahs and praying well from now on, but also the level of your faith and how you want to improve your own relationship with Allah by showing your appreciation for the opportunity to gain knowledge and be given guidance before it was too late to do so.
This means several things to different people. To give just two examples of what I mean-
For some, it is about looking for relatives or friends, neighbours, work colleagues who are similarly far from Islam and attempting to rectify their Deen and making them better Muslims by helping them in some way or another. If some of them don't pray, even just reminding them every so often can be sufficient as an example of showing gratitude to Allah.
For others, it can be teaching large numbers of people whatever knowledge you have and guiding people about wrong ideas they may have (Bid'ah), Fabricated Hadiths or some misguided cultural beliefs that have no place in Islam. I know of people who just visit sick people and treat them with kindness as a means of being closer with Allah.
There are hundreds of ways you can enhance your status with Allah and show you now want to exchange your previous account with a higher role in the future and only you alone can decide how much further you wish to go, but the opportunities (and rewards), especially in current times where practising Islam fully, is not as easy as it once was, are so much grander and greater.
