Congrats on getting started!

I agree about not trying every day and building up to it.

My commute is about the same length as yours and has a good climb in the middle. At first I couldn't do two days in a row. First I did 2 days a week, then 3, either M, W, F or two days in a row then a break then a third day. I eventually got to the point I could do 4 days a week, usually taking W off. I tried four days in a row and it was really hard the last day. I don't know if I will ever do 5 days, partially just as there always seems to be one day that my schedule makes riding impractical.

On your off days, try to do a good walk or even a very short ride or you will likely be even more sore the next.

Good luck and have fun!