Well now they are two very seperate issues.
As to the intercession of saints.
Jesus Christ is the head of the Catholic Church. He is our first Priest, it’s His Church.
We are the body of the Catholic Church, we being the Communion of Saints. This Communion of Saints consists of the Saints in Heaven, the souls in Purgatory, and us faithful on Earth. Now we, the living , are not obliged to agree with the intercession of Saints. We can pray directly to the Trinity.
People seem to have one or two fav Saints though. When we are kids, especially at Christmas, we are quite happy to know St Nick. And Our Lady and St Joseph, her most chaste spouse.
As far as disagreeing that Communion bread and wine becoming the Body and Blood of Jesus Christ,
Jesus gives us the example of doubting Thomas, His Apostle. Thomas had to feel the wounds of the Crucifixion of Christ, the nail holes in Jesus hands, the wound in Jesus side, before Thomas believed in the Resurrection. Jesus had no problem showing Thomas, and accepting that Thomas had doubt.
Jesus knows, as with Thomas, we are human.
We are Pilgrims on the road to God, the road home to Heaven. Doubts and struggles are part of our Journey. And part of our formation to conform to Christ.
How’s that?