Need help to get prepared for Tournament

Hello everyone !
I m going to participate in Open Polish SFV PS4 Tournament.
I have alot of experience in all kinds of fighting games but not as much as SF series. I have played SF IV (and older) in the past but I need some information about SFV becouse unfortunately I haven’t got a chance to play the beta.
1.Are there any BIG changes to the core mechanics (Excluding V-Trigger) that I need to keep in mind or basic knowledge will suffice?
2.What would be the best character that would be good and rather easy to learn in short time?(16 is premiere of the game while 20 is the start of Tournament elimination)
3.Any tips/information (basics are not that necessary :stuck_out_tongue: ) about SFV would be really helpful I blog about shit like what you are asking.