First off, congratulations!

The only apartment I rented in Worcester was found through a friend, so I can't help much there, but Craigslist is probably a decent place to start looking. WPI will likely also have resources to help you find housing.

To echo what everyone else is saying, you'll need to be prepared for it to get quite cold in the winter (consistently below 0°C December through the first half of March, with dips down to -20°C and a couple days even colder). In the summer it can be really warm (25-30°C with the occasional day that gets to 35 or so).

If you aren't familiar with the cold, the best advice I can give you is to make sure you have layers, including a base layer (merino wool ideally). Get a solid pair of warm gloves, a warm jacket, some decent boots, and beanie or two. The best time to buy this stuff is between now and September or so, as it will generally be on sale. Locally, most stores won't carry much in the summer but you can always shop online.

You 100% need a car or reliable access to a car. The bus system is not great and Ubers/Taxis will add up quickly. Also, one of the things that's great about Worcester is easy access to the places and outdoor activities nearby but outside the city and those can be tough or impossible to get to without a car. It would be a a shame to live here and not get to experience the rest of New England.

Best of luck with the move.