Calling out definitely isn't going to look great, but if you haven't called out before, I wouldn't sweat it too much. I would actually start by putting your shift on the swap board first, to see if anyone would be willing to take the shift for you. Since it's a few days beforehand, and a lot of TMs are looking for more hours, it might not be too hard to find someone to take it for you. Then, if you can't find anyone to cover for you, you'll have to call out.
That all being said, I would make sure that your availability is set differently for each of your jobs. For example, if you said that you're available to work all day at Target on Saturdays, you have to tell your second job that you're unavailable on Saturdays.