Meeting your spirit guide can either be in dreams or meditation. I prefer meditation though. 1 simple yet effective way to meet your spirit guide through meditations is this:
1. Get in a meditative position (Make sure your comfortable)
2. Say in your mind "I will contact my spirit guide" for like 30 minutes (up to you how long it takes)
3. Sure enough, you will go into a trance like state. You will see a vision of how your spirit guide looks like, what's the guide's name,etc.
Note: This takes serious practice, to some people they can do this fast and don't need that much time, but to those who can't persevere and you will unveil knowledge.
A method of going to this through dreams is this:
1. Write in a piece of paper (Any paper) these words 3 times or more:
"I will contact my Spirit guide"
Note: Write this before you sleep, not before you brush your teeth, not before you say goodnight to anyone, exactly before you sleep.