It’s hard to diagnose what’s going on without more details. How long ago did you install WordPress? is this a VPS, shared hosting, 1-click install, DreamPress or what else? New domain or transferred domain? what’s the error message you get?
If you want a quicker answer without having to diagnose the issue yourself, open a ticket or start a chat session like @LakeRat suggested: DreamHost support staff will immediately see what the problem is and fix it for you.