This a fun thing to do but take's some getting used to warding is very vital to do this because well mid lane is always a hotspot and being a Sona only make's it worse. This does not come easy you will not be fed your first most likely because you're still a support in mid with assassins and heavy burst mages. You will need to take some time in order to learn this i will try posting some Youtube guides for this feel free to ask me anything and fill me in on your success or just experiences i am very busy but i'll try and look at anything said have fun trying out Sona mid.