Hey Rezia, the following advice is very much general advice. I can apply to anyone (ie. someone looking at getting into Christianity, atheism, a My Little Pony fan club...).
I am really sorry you are facing such opposition from your parents. I do understand how that feels, though for other decisions entirely. It took hitting 18 and moving away from home for me to be able to even begin making and living by my own choices.
When looking at joining in on any sort of group/practice, be careful of surrounding yourself only with material, publications, and views from the same group you are looking at getting into. If said group teaches you not to respect the choices of others, that is a huge red flag to be wary. Groups of people being demonized is always something to look out for, whether it is directed at vegans or meat-eaters. Read and discuss widely (though starting with people you know respect and will listen to you is a great first step), and fully consider each angle. Be able to get to the point where you can face opposition and respond calmly to it. Look at facts and make sure you explore your own reasonings for doing something. I personally hate trying to hold a conversation with someone who can only seem to spout back a series of bumper sticker slogans back at me. That is to say, many people I speak with tend to parrot what they hear instead of actually thinking things through for themselves and looking into things themselves. A good example for veganism would be, "meat is murder". Above all, understand that what works and is true for one person, is never going to apply to all people (including the advice here).
I find that when I do the above, I can remain more respectful of others (instead of just getting angry), and that more often than not, I will get a better reaction/more thoughtful discussion/less disrespect in return. I also find that even when this does not occur, I can be more confident in my personal choice, especially when I am only trying to apply it to me and my personal behavior.
It sounds like you are already well on the road to having a balanced and informed view, and I hope that will give you the confidence to continue on your journey!
ps. Look up chia seed pudding. It can be made with non-dairy milk. Adding cocoa powder and a sweetener (I use honey, but something vegan-friendly like maple syrup could be used) is my favorite flavor. It is really filling and is one of those foods that is as delicious as it is healthy!
