Exodus 34:26 - The first of the firstfruits of your land you shall bring to the house of the LORD your God. You shall not boil a young goat in its mother's milk.
God does not want to be the extra thing we do when we have extra time. He is not the cherry on top of our sundae of life. God desires, demands, and deserves the first of our firstfruits. He desperately desires us to enter into a loving relationship with Him. As the moral lawgiver, He demands that we order our lives rightly, which means that God is first. Finally, as the only perfect and holy one, he deserves to be placed first in all things in our life. Understanding any one of these reasons to place God first opens our heart to seeing more of Him, but we must pursue all three reasons to get the full picture of who God is, who we are, and how God sees us.
Also of note: at the end of the chapter, Moses comes down the mountain from seeing God and HIS FACE IS GLOWING. Like, actually, full on, glowing! To the point that the Israelites were afraid of what they were seeing. That is an experience of God that I want!
I should also point out that I am reading through the 'New Testament+' plan from OWNit365 right now. For five days of the week, you read one chapter from the New Testament, and on one day of the week you read a chapter from the Old Testament that relates to the New Testament readings of that week. Then, there is one day off to help you catch up, if you fall behind. It is a really great plan and the OWNit365 website has a ton of great resources to help you study. There are great videos for each book of the Bible that give you a good intro into the themes of the book and a lot of other stuff. Check it out!