How do you tell how much "playtime" your newborn needs?

Clara is 9 days old. I know that she needs to engage with us by making eye contact and hearing our voices, and with lots of cuddling and so on.

I know that she needs a lot of sleep.

But I don't know how to tell how much playtime is enough and how much is too much.

The last couple of days we've had stuff going on in the household in the afternoon: family visitors and then yesterday we took her for a walk in the park, for 15 minutes, to get a look at the "big wide world". Both days she came home and couldn't sleep for hours. She was reasonably calm while we were holding her, but crying every time we put her down. I figured it might be overstimulation. So today we've had a really quiet day, and she does seem to be going to sleep now, at a time when yesterday she was all upset and cranky.

But the idea of her just waking, nappy change, feeding, and being put to sleep again 10 minutes later all day and night seems wrong to me to. Shouldn't she be spending a bit more time than that interacting with us? I would hate to be boring her by not doing the right thing.

Clara is sleeping in a "co-sleeping cot" by my side of the bed, and one or the other of her parents is there a lot of the time anyway, because we are really tired. So she isn't alone that much of the day or anything. I want to try carrying her in a sling for a while in the daytime, as soon as my C/S wound is healed enough that I can physically handle it.

How much time does your newborn spend sleeping?

How much time does your newborn spend doing anything other than sleeping, feeding, and being dressed/nappy changed/bathed?

Any suggestions would be most welcome. I am really new at this.