If you are in Beis Yisroel, then you are easy walking distance from Ohr Sameach. It’s located at 22 Simon Hatzadik. I would recommend you just go there to daven Ma’ariv, and see what happens. It can’t hurt and it might help.
Before you go there, look at www dot ohr dot edu/study-in-israel/
You will see that Ohr Sameach has three parts. One is as for secular Jews. The second is called intermediate and the third is advanced. I’m not sure you fit in any of those, but it can’t hurt to ask.
Even if you don’t fit in there, the rebbeim at Ohr Sameach can probably direct you to a yeshiva where you will have a better chance of success.
Here is a completely different way to approach the problem. It might be easier to go to a Shadchan and ask what you need to do to get a good Shidduch. That will give you a goal – which will give you motivation. Are you interested in a girl from N’vei Yerushalayim? If not, so what are your realistic possibilites for Shidduchim? Where would you need to be in a year in order to be ready to get married?
Congratulations on your desire to do tshuva and may Hashem help you accomplish it.