For the most part it seems like you've gotten a lot of good feedback, I'd also like to add that it'll not only help to look up tutorials but also see how people have implemented animation or gifs into their own comics. just to give you a point of reference.
I can't recall the name of the comic but there was a series featured on tapas that included a large number of animated panels. there's likely a handful of those on tapas if you look around it's just a matter of searching.
also software that I'd recommend for animating would probably be firealpaca. its a good beginner software and free. finding tutorials on how to use the program shouldn't be too difficult and as for its animation tools it's mostly a simple onion skin layer mode which is good for those simple frame by frame animations.
also something worth noting is if you're going to be uploading GIF panels or animated panels into your comic you'll have to pay attention to compression and file size because if you're putting it on tapas they've got limits to that so you'll have to check it in the upload section. as well as paying attention to your file sizes.
hope you're able to work things out 