How can i be a better muslim?

So the thing is im a muslim girl and i pray and everything i know my kalimahs, but sometimes i intentional dont pray.i feel like im following shaitans road when i do something wrong, i just want to strenghten my iman. Also i used to be friends with someone who i thought was a christain but found out she didnt follow any religion at all. she put nasty thoughts in my mind, so i stopped being her friend. i dont beileve anything she said but i want to get her nasty words out of my mind. i see her everywhere since she is my neighbor so it is really hard to forget about what she said