Just talk to Him as if He were you're friend. He knows your heart, so He knows that you love and reverence him. so, start by telling Him how much you love and thank him for what he has done for you.
Pray for others
We should always pray for each other because prayer creates unity. As we pray for one another, the very act of praying for someone else builds the love in your heart for that person.
When you pray tell the Lord what you are in need of , Salvation, Healing, Finances, New Job etc.. Be specific about what you want God to do. I encourage you to write it down.
To know if what your asking is in his will you can find a passage that applies to your need or desire so you can petition the Lord based on the authority of His Word. Once you have that verse and can pray it with confidence, go right into the presence of God and boldly ask Him to work on your behalf (see Hebrews 4:16).