It's almost always best to start with an application. What do you want to do that involves moving a lot of data around while performing some hard realtime processing on it? The answer will tell you if FPGAs are a good fit for the job.
Assuming they are, the answer will also give you an initial handhold on the mountain of training and R&D work that you'll need to deal with to make it happen.
Assuming they are, the answer will also give you an initial handhold on the mountain of training and R&D work that you'll need to deal with to make it happen.