Step 1: Ask your coach ... she will give you guidance.
Step 2: Ask for a referral to a good boot fitter.
Step 3: Go see good boot fitter ...
Nobody can tell you what boot you should be wearing except for a good fitter and a good coach; without seeing your feet, your build, and your skating style, etc. A good fitter is worth your time and money. Once you find a brand that works for you, then, stick with it - and if it's not the same one that everybody else wears at the rink, then, that's just fine if it works for you.