Lawrence is a cute little town. Most dining and entertainment options will either be on or just off of Massachusetts St, which it itself a pleasant stroll as long as it's not (basketball) game day. If I were in Lawrence for a weekend, these are the places I'd prioritize:
--Replay Lounge, for some live music and cheap beer in a gritty, casual setting
--Love Garden, for buying some music to take home with me
--Teller's, for brunch in an old bank vault
--Local Burger, for, well, a local burger (but a very good one!)
--Jefferson's, for fried macaroni and cheese
--Free State Brewing Company, for some basic American brewpub fare and a touch of local history
--To go a little deeper into local history, you might also be interested in the self-guided tour of Quantrill's Raid
. I've never done it, but would if I were there now.
Edited because Massachusetts Ave is not the same thing as Massachusetts St, and I am talking about Lawrence rather than Boston.