The town of Tulum isn't very interesting, it's basically one main street with shops and a lot of souvenir shops, and some small side streets. The hotel zone is on the beach an quite far from the centre, it's best to catch a shared taxi there. As far as I've noticed, Tulum is a safe place and you have nothing to worry about.
I visited the ruins by the beach, which are only nice because they are the only ones in Mexico by the water, and spent a day visiting the ruins in Coba, about an hour away in the jungle.
I stayed at Camping Chavez, a super cozy hippy-campsite with tipis and a shared kitchen. For food in town i recommend the first 3 restaurants at Calle Jupiter Sur, just around the corner of the main street and across from the ADO busstation.
Hope this helps :) about 4 years ago