Hi @rachelcoles
First, the standard warning - it is really hard to offer settings because so many things are different between your setup and the original. You will generally find folks wonāt even respond with useful info.
Ok, since i donāt like the above response, hereās something to get you started.
You are pretty early in your learning, so donāt get tied up in making yourself sound too close to the original. If you set a goal to make sure the song is clearly recognized, that should be a great starting point for you.
As I listen to Justinās lesson there, it sounds like he has a bit of distortion, the bass is a little quiet and the mid and treble are about the same. I strongly recommend that you mostly balance out the bass, mid, and treble to get the general tone in the right place and consider that a success.
What I tried: high-gain plexi channel with gain about 4, bass about 2, mid about 4, and treble about 5. I tried some other amp models as well, and could dial in something pleasing. I am choosing plexi here since your amp probably has that model. Use the bridge pickup on the McCarty, guitar gain way up, and tone towards treble - maybe max, then adjust as you think it needs.
On the Cream original, I think I remember more distortion than Justinās. You are likely to find that hard to control - the string noise will come right through with gain higher, so turn the distortion (gain) down so you can enjoy playing the song. Expect controlling noise to be difficult for you at this point!
I think Clapton was using an SG back then, and the SG will be very chimey sounding compared to your McCarty, so this is why I think the guitar tone will need to be far toward treble. Might just be my hearing is bad too, and I am going by memory.
Again, donāt try to get the sound exact - you probably wonāt for a lot of reasons (recording is mixed, SG is lots different than McCarty, amp is differentā¦). Timing of that riff will go a long way to making it sound right, even if the tone is not all that close.