Sperm analysis question

Ashleigh • Engaged to my best friend and soldier. We have a 5 year old son, and currently ttc our second ❤️
I have a five year old from a previous relationship. My husband and I have been ttc since January. I know I'm not supposed to worry until I hit the big year mark, but how would we go about having a sperm analysis done to check and make sure everything is good on his end? Where do we go? What do they do? What do the check for? What should we expect? Sorry for all of the questions, this is new for us this time around.