Amy,

The answer to both the questions is a resounding Yes!!

There is no sin which God will not forgive except for the refusal to accept forgiveness.

In the Church, forgiveness is routinely administered through the Sacrament of Confession. God can also forgive you without this process, but often times our remorse is not perfect. Through the ministry of the Priesthood, Christ makes up for whatever imperfection exists in our remorse. It is also a source of grace that strengthens us to stay away from further sin, and most importantly by hearing the words:

I absolve you of your sins.

we also can begin to forgive ourselves.

Remember, while Jesus was hanging on the Cross, He asked the Father to forgive those who had crucified Him. The message of the Cross is forgiveness, Mercy, redemption, and salvation.

On your second question:

The Catholic Church is not just the first religion based on Christ. It is the only Church founded by Him. All other groups, claiming Christ as their Lord, are offshoots of other religions.

I hope this helps.

Under His Mercy,

John DiMascio