Starting IUI process this cycle

So my doctor wants us to start our first IUI process this cycle. Should be getting my period on Saturday and then start letrozole at CD3.

I just started a new job so I’m trying to figure out how much time off I will need for appointments. From what I understood I will need a ultrasound appointment around CD10-12 and then a insemination appointment. Is that all?

And how will they know when to inseminate? Do i have to opk test?

Sorry, doctor probably told me all of this but I blacked out as I was pretty upset about my infertility journey.