First sweater

Ok I have a few questions. I am doing a raglan style hoodie and I have all the pieces done I have seamed up the sleeves and both sides to the body but I am now to the point where I am sewing the sleeves to the body but I am confused how to seam up something that was decreased it comes out kinda lumpy.

Also the sleeves are a bit tighter than I would have liked not by much but I was wondering if I could go back and takeout the seam and add a bit or should I just leave it alone.

Thanks for all the help kisses :heart:

I’m lousy at seaming sweater sleeves so I’ll bump this for someone who knows more.