from my experiences playing as sonic, Sonics playstyle revolves around hit n run tactics, u have so much speed to get in and out before your opponent cant react at all. Sonics floatiness can easily help out aerial over profectile spams. Dash attack is one of the easiest ways to start your chain of attack especially if u do a dash attack and return with a spin dash back jump bump and use neutralair then finish off with a well timed homing attack.
Getting to the finisher, sonic has an extremely strong chase tech, if u master his dash jump and forward air that carries alot of momentum, u can keep pushin your oppoenent off the edge with ease and once at the ledge its extremely easy to gimp slow chars recover cuz homing will amlmost always hit them and guarantee their doom. Smaller chars like fox are too fast and homing attacks off stage will most likely end up in an sd. His down smash is easy to land as well and has like the 2nd to most knockback on his list (first being his fsmash which is very situational but xtremely effective), it has superb range and can be applied in many close combat situations. Setting up the target is very important as sonic, since his speed allows him to get a large range away from oppoent. his dash to uair range is alittle hard to master at first but once u get it it can start some nasty juggling.