There was some Krausen remains, but not a ton. Where I put in the hydrometer was clear though.
Just to be clear, since I'm a noob, if I pitch more yeast do I need to shake it to aerate again, or just put it in an seal it?
Amount of krausen, just like airlock bubbling is one of those things that really isn't an accurate gauge of fermentation, even if you split a batch in half of the same wort, and put the same yeast strain in the two fermenters you could get two different amounts of krausen.
I can't stress this enough, visual signs like airlocks or krausen development are NOT accurate gauges of things. They can be affected just as much by environmental factors and actual fermentation... That's why the only gauge of fermentation is a change in gravity...nothing else is reliable.
No, you should not shake at this point, you DO have beer in there. Oxygen is the enemy of fermented beer.
Just put the yeast in, and WALK AWAY for another 2 weeks. Don't even look at your fermenter.
I'm sure you don't really need to do anything. I've been brewer for a ton of years, and NEVER had yeast not do it's thing. I think too many times new brewers think they don't have fermentation, and hover over theri fermenters worrying and micro managing thinks that don't need to be worried about.
I wouldn't add yeast, but at the same time I just pitch my yeast and come back to bottle or keg in a month, and my beers have all turned out fine.
But I know it makes you feel better, and it won't hurt anything.