Don't worry about that! I will try to talk as simple and clean as possible for you <3
Sonic is very annoying and fast and a bad Match Up for us. However, it isn't unwinnable. I personally rate this MU 42.5-57.5 in Sonic's favor or -1.5. I believe this Matchup is our second worst MU.
Some things you need to note about this match up.
The reason I think this Match Up Is hard.
1. It is extremely difficult to edgeguard/gimp Sonic because of his recovery. Why does he have invincibility in his recovery i don't know.
2. Sonic can easily punish most of our attacks from any place.
3. Sonic can repeatedly edgeguard us until we die.
4. Sonic is waay too fast for our subpar Frame Data.
5. We lack good aerials to beat Spin Dash
6. Our fastest Aerial move is a frame 7 Nair and Frame 7 Uair, and that is a pretty small hitbox for Nair and Uair is unreliable.
1. You can grab Sonic out of Spin Dash and Spin Charge. Make sure if they ever spin charge towards you, you get that grab on them.
The following hits Sonic out of Grounded Spin Dash:
Forward Air
Down Air
Zair
Back Air
Neutral Air(Very hard to do so)
Forward Smash
Down Smash
I think Up Smash?
PK Fire
PK Freeze
PK Thunder
PSI Magnet
Grab
These Clank with Spin Dash
Down Tilt
Jab
Your best option in most cases is to grab if you predict the Spin Dash, if the Spin Dash is far away, or you are right in front of them while they are charging Spin Dash. Otherwise, you want to wavebounce PK Fire as the other options that beat Spin Dash are hard to land. Practice the PK Fire where you do a short hop and make it where the PK FIre is at the lowest possible position it can be.
Sonic has punishable options, but the only time you would want to grab is if you predict Spin Dash, read him, or he does Up Smash or Down Smash or whatever. Otherwise, use your tilts, aerials, PK Fire to punish. Never use PK Freeze unless he is way offstage. You can also try challenging his Up B when he grabs the edge with Nair or Back AIr as Nair has lingering hitbox of 16 Frames while Back Air is 6 Frames. If you Nair right at the edge of the stage where you can grab it, you will stage spike him as it will be impossible to tech.
That is all I have for you. I am still trying to learn the MU unfortunately