Can my dress be altered??

Hello everyone!! So I was obsessed with my dress from the moment I saw it online, I tried to find a shop that I could try it on at and no one in the state carried a sample! So after months and months of obsessing over pictures and saving I bit the bullet and bought it online. It just came in today and it’s so gorgeous! It definitely needs to be taken in a little bit and I’m hoping that’s what’s throwing me off about it, but what I’m worried about is I feel like the waistline hits just slightly too high on my body. I tried googling about lowering the waistline but couldn’t find much info! Is that even possible to do?! Could they maybe lengthen the straps a little to drop the waist a little lower?? Help 😭
I’ve never bought something so expensive before and I would hate to have to return it and start over.