I think the first thing to do is to unplug it, wait 20 seconds or so, and then plug it back in. Does it work better now?
If not, my guess is you have the Echo placed in a weak Wi-Fi signal area of your home. Place it closer to the router.
If still having problems . . . . .
You are entitled to free phone support from Amazon, so use it!
1-877-375-9365
From an Amazon email: “You can reach Amazon Echo Customer Support by phone directly and toll-free at 1-877-375-9365. We're available from 3 a.m. to 10 p.m. Pacific time, seven days a week.”