What do the 可 mean in 可现在想起来可真是记忆犹新呀 and 我可要出点丑了?
可现在想起来可真是记忆犹新呀！

The first 可 is the abbreviated form of 可是, meaning "however":

The phone was intalled a few years ago, however, I still remember it as clearly as if it's yesterday.

The second 可 is used to emphasize 真是. This 可 can be omitted.



我可要出点丑了！

Here 可要 is used to draw more attention from, or to give heads-ups, warnings, or threats to the listeners. 可要 can be reduced to 要.

出丑 means to reveal something shameful or private about oneself to others. 出点丑 simply reduces the amount/intensity of the 'shame' being revealed.