When I was teaching I worked middle school at a place that was mostly Hispanic kids and the majority of our school was on free and reduced lunch...I think it was something like 68% if our kids.
Relationship building is key. You want these kids to know that you genuinely care, they are not a project for you. Respect the kids...even the ones that don't show respect in return. You have to constantly model. Relationship building does not necessarily mean that you are everyone's buddy. You are their teacher, not their friend. Don't lose sight of that, because sometimes that is a hard balance to maintain.
Reach out to the parents. Email them if possible. Call frequently. Don't just call for the bad stuff, call for the good too. Opening the doors of communication will help a lot. You will gain insight. and trust
I would encourage your school, as a whole to try and get parent involvement. Even with the language barriers we had to deal with, our school, over time, was able to get parents coming to school and interested. Granted, they were basically bribed to every event with pizza dinners, but it worked. Math night, reading night, open house, etc.
Own your classroom. You are the boss in there. Don't get bullied and don't show fear. I am a pretty relaxed teacher. We do a lot of group work. I play classical music during seat work. I like manipulatives and hands on where applicable (I taught math). I like kids working together, talking and thinking. But the class does not start there. I start strict. Rows in lines, no talking at inappropriate times, etc. You have to teach these kids what behaviors you expect. Slowly, you can relax the rules and environment in the class. But it needs to start out all business.
Have high standards and expectations. Regardless of what you have heard from others, they can meet these expectations. It just sometimes takes more work. I would also avoid teacher "gossip". You will find more than one teacher that wants to tell you how horrible this kid is or how rude that child behaves...stay away from that talk, you will come out with judgements about kids. Now you DO want to know that Johnny is late every day because he has to drop his sister off at the sitter or Suzy watches her siblings every night while her single mom works the night shift. This sort of information can help you teach these kids, find a system that works.
While teaching we had to read the book "Understanding Poverty". It helped up understand some of the actions of our families and why they make the choices they make. I would recommend that book.
Good luck!