Here's a more official explanation:
https://www.catholic.com/encyclopedia/sacramentsÂ
Here's some clarification on some:
The Eucharist- This is the body, blood, soul and divinity (aka His entirety) of living Jesus Christ. His physical presence unites with ours, although we don't see it, when we eat the host or drink from the chalice. He only appears as bread and wine. Why would He do that?
So we can express love and obedience in participation
To forgive our sins
To heal the soul
For the resurrection of our bodies
For the occasion of gathering in his name; "Do this in memory of me"
For ultimate perfection; communion with God
To experience joy and gravity
One could ask 'How can God be in 3 persons if He is one?' There is the reality of God, undivided, and there is our universe, which has divisions. God is manifest to us as 3 persons. With the Eucharist, we become whole, 'realized' with Him. He is displayed as bread and wine because it is nourishment he offers on our way to Him. His physical body is more than located. It transcends what we sense. What we sense is our task, the truth of the natural world. When we voluntarily receive Him in His ritual we fulfill and renew our purpose and return here to serve and love. In that way we continue to display Him. We are needy, His love is the answer. Truth, Beauty, and Good (Justice) are our mission. Eucharist is success! He expresses his love and embraces us through this ritual. It's more than being present.
Confession- Some of us sin often, and when we commit grave sins we should find a priest and confess our sins asap. Even if our sins are not great we should go to confession (usually on Saturdays) once a year AT LEAST. This is for the forgiveness of grave and minor sins.