Welcome to MFP. Depending on what your goal weight is 50 can be a reasonable amount to a lot that could be difficult to reach. I started with a reasonable goal and it went up a few times but my main goal was to take my time and do it in a manner that was healthy and one that would instill long term habits.
So my advice is to take it slow, when making changes to your diet think in terms of can you live without this forever or can you reasonably limit this particular item - I knew coffee, bacon and ice cream will be in my diet forever. I learned how to manage them, and in some ways now I enjoy them more. Limiting some food to initially lose weight is okay but you have to know yourself and if once the weight is off are you going to be able to maintain the loss. Take some time to learn portions - it can be a real eye opener. Like why do cookies come in a pack of 30 when only 2 are considered a serving Can you eat 1 serving or will you eat 4 and call it dinner - this won't work because its not healthy and won't work long term.

If you are looking to get active (I prefer active over exercise because you can always find time to be a little more active) just think about moving more, if you do go to the gym and it is your first time, please take your time and start slow, light and short before jumping into too much and them being down with an injury.

50 Pounds can seem like a lot but it can come be done, just take your time and keep your health in mind at all times.

I have the same concern. I want to lose about 50 but keep going back to those same old habits. Thanks for the advice from the other posts. Going to make this time different!