Aside from using sandwich technique to minimalize potential irritation, you could as well opt for retinyl esters (e.g retinyl palmitate) or the weakest forms and slowest ones in showing the result but arguably safer for beginner. I myself have just begun to use retinol 2-3 months ago and chose retinyl palmitate as the option as I personally still quite scared of using retinol, in case I haven't work well on hydrating and protecting aspects, as I also just began to build a solid basic skincare which works best on me.
I did patch test and work slowly from once a week to 2-3 times until finally now I can use it every day even though it is said the weakest form, and fortunately my skin reacted well since the day one. I'm also happy to share that the results are great, I have notice many recognisable improvements since incorporating them (toner and moisturizer) into my routine.