Yes there's a Trinity. Here's some scriptural reference.
Colossians 1:15-23
The Supremacy of Christ
***15He is the image of the invisible God, the firstborn over all creation. 16For by him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things were created by him and for him. 17He is before all things, and in him all things hold together. 18And he is the head of the body, the church; he is the beginning and the firstborn from among the dead, so that in everything he might have the supremacy. 19For God was pleased to have all his fullness dwell in him, 20and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross.
The Trinity can be hard to comprehend and hard to explain...How can someone be three in one? I try and use analogies. For example, H2O- there are three forms of water-solid (ice), liquid, and gas (vapor). They are three different forms, but it's still all water. Our own bodies are 3 part beings:Mind, body, and spirit, but it's still all me.
There are things about the Trinity that I STILL can't completely grasp and I've been a Christian for a long time. I just think it's one of those things that's hard for our little minds to wrap around. It makes COMPLETE sense to my spirit-man, but at times my mind is like "say wha?"