How do you LEAVE everything and follow Jesus?

It is a principle decision to follow Jesus at all cost and to do what He guides you into doing.
Firstly you need to dedicate your life to Jesus and obey Him, live holy and righteous in obedience to His words, as written in the gospels: Matthew, Mark, Luke and John.
The Holy Spirit will also convict you in your heart of sin, righteousness and judgment. Obey His voice speaking in you.
Jesus will reveal Himself to you more and more and convict you of things that you need to stop doing, bad habits, thoughts etc. Obey do not resist. If you need to stop hobbies and get rid of wrong friends, LEAVE them behind.
LEAVE your own interests and desires behind and seek to please Jesus.
Ultimately He may guide to go to wherever He wants to use you. Then, LEAVE everything behind.
Make sure that you follow Jesus and not your own mind. You will eventually need to leave your own mind behind and focus only on the guidance of the Holy Spirit.

Jesus does not lead you to leave your responsibilities. You need to take care of your family and honor your commitments, work and earn an honorable living. He will not allow us to desert our responsibilities.

Get to know the voice of Jesus and follow him. His sheep do. John 10:27.
Those who follow Jesus do nothing on their own initiative, they do what the Holy Spirit guides them to do.

How can I strengthen my love for Christ and God?

Jesus said:"Why do you call Me, 'Lord, Lord,' and do not do what I say?" Luke 6:46 and also: "If you love Me, you will keep My commandments." John 14:15.
We demonstrate our love to Jesus through our obedience to His words. Obedience to Jesus carries a high price. If we obey Him we will be rejected, scorned, mocked, persecuted and even killed. The strength and increase of love comes through the endurance. As we endure, even in the face of difficulty, our love for Jesus will increase.

What is our cross, how do we deny ourselves?

And He said to them all, If any man will come after me, let him deny himself, and take up his cross daily, and follow me.

What is our cross and how deny ourselves?

Our cross is our flesh, our sinful nature. We must disallow ourselves our own desires and pleasures and deliberately do the will of God, which means that we obey the words of Jesus and follow the guidance of the Holy Spirit.