At night I use Retin-A cream 0.05% then I moisturize. Can I apply Aloe vera gel straight from the plant on my face after?

When using a Retin-A, you want to give it about 20-30 min to settle into the skin before applying anything else on top. As long as you have waited that amount of time, you can apply any moisturizers you would like. I would suggest applying the aloe vera before the moisturizer, if using them both.