Omniscient means “All knowing” (1 Jn 3:20 see CCC 208). God has infinite, unlimited knowledge. As the creator who sustains creation at every instant God knows everything that takes place within the order he has established. God is also outside of time as time is a part of the physical world. This also means that God’s knowledge of all things is a single act, He cannot learn or forget, He simply knows. He knows every possibility. He knows what every person has done and what every person will do, or could do.
God knows what He has made you for and knows which path will lead to your greatest ultimate happiness. If you follow God’s will, this will be the path he leads you down, it may be hard, but it will be the best. This path is what we call your vocation, your calling.
Omniscient: God “knows everything” (1 Jn 3:20 see CCC 208). God has already thought of every possibility, both good and bad. If he hadn't he would lack something and therefore not be infinite. God knows the future. God is transcendent. Therefore God knows everything about you including your future and what would make you happiest. He has a plan for your life that you can only experience through him.