Most people start with a good beginners book, and if you search here for that you will find book recommendations. Try the search string “beginner book recommendations”.
Work that from start to finish and see how you feel.
We have many free tutorials here provided by members if you don’t want to spend any money: search “tutorial evocation” or “evocation guide” or for whatever you’re looking for. The forum is over 10 years old there’s a lot. 
We have collections of tutorials in fact.
I recommend you start with developing psychic senses and spiritual hygiene. It’s not useful to you when you can’t psychically see or hear them when they come, or if you can’t tell that what came is a parasite.