Welcome to the forums Jen

I would apply the Topix Replenix Retinol, wait 30 minutes or so then the Olay Regenerist Daily Regenerating Serum. You want the active ingredient in the Topix product closest to the skin so it absorbs better. Moisturiser would then go after the serum.
You should really be leaving 2 weeks in between introducing new products. It can take that long for reactions/breakouts etc to start to show.