Solid doors are generally fairly soundproof but nothing is going to be 100% so you would also need to use other soundproofing techniques depending on how sensitive you are and what the issue is.

I had cheap hollow doors which I replaced with solid doors and the lower sound is noticeable when I close a door.

Fabric, rugs and upholstered furniture absorb sound. White noise machines help if the issue is someone being disturbed by sound coming from the hall or anoth room. Acoustic material cam be applied to walls or even into walls.

We have a house with a similar design, it sounds like, except a couple of decades older. Our house still has its original solid wood doors and when they're closed, they do a very good job of buffering sound. (When they're ajar, as my kids are constantly leaving them, it makes a huge difference in what you hear.) If you have hollow core doors, swapping them to solid wood would likely make a big difference.

ETA: Also, probably a bigger project than you're looking for, but we are doing work right now with some walls along our bedroom open, and are taking the opportunity to add insulation even though they're interior walls. No idea how much this will help, but it can't hurt!