"To" is used to give a reason, talk about direction, transfer or distance. "For" is used to talk about a reason, help, time and schedule. “To” is used to give a reason with a verb. An example: “I'm here TO HELP you”. “For” is used to give a reason with a noun. An example: “I want to help you FOR your test”. About directions. “I’m going to go TO Brazil”. “I’m going TO the grocery store”. Use “To” when stating where you’re going or intentions to go somewhere. “For” and “To” can be used to describe a time span. An example: “I lived in Boston FROM 2005 TO 2015”. It’s from one year to another. “For” can be used alone to describe time. An example: “I’ve lived in Japan FOR two months”. I hope I was helpfull.