OPK ignorant

So I have 3 beautiful, badass kids, but I’ve never actually tried to get pregnant. I know, some of you are thinking “ugh go away you lucky bitch.” But now I’m starting to actually try for a 4th. My husband has some fertility issues, so we decided to track ovulation. My questions are - do I really need to hold pee for an opk? Are digital opk’s better than cheap Amazon strips? If I have a regular 28 day cycle, should I be testing twice a day at this point? I’ve been testing once a day and I’m on CD 11. This is our first month so I’m not stressing, just curious because I’ve never used opk’s. 🤷🏻‍♀️

Here’s a picture of our nerdy selves.