Recently I created an account with intent to upload comics, but when trying to pick a payment processor, I noticed a PayPal option was absent, and only Stripe is listed. Is there some way to active PayPal that I'm missing? 

I've contacted support but didn't receive an answer, so I'm wondering if I just haven't clicked on the right thing, or if my account is too new.

Any help would be appreciated!

I looked into this as i was also confused.  Found out that a scammer abused the system so they have had to disable it on new accounts I think.  It's also absent in my options.  Was hard to find any information about it in google.  You may have to contact support to ask them to enable it on your account.

*Edit

Looks like you can only use paypal now if itch collects your payments for you, and after each payment you have to wait 7 days before you can cash it out.