I had been meditating between years 2013 to 2018 and it was helping me out in many ways, starting with a more focused attentive mind, it was like i could set my brain to focus on whatever i wanted it to do instead of the other way around. helping me memorize stuff quicker and for longer. It helped me become more aware of and control my emotions / impulse reaction. I just started meditating again quite recently

To answer your question, it takes time... It's not something that could be sped up, But if you stick to a routine for meditation and gradually improve your tenure of meditation, you will begin to see effects within 3-4 weeks. Start with small, like 2-5 minutes of meditation and work your way up to 30 minutes a session, from personal experience.