Key wording options in Lightroom

I am a keen amateur picture taker.

I am contemplating making the move from LR Classic to CC primarily to take advantage of the mobile benefits. I nowadays use my iPhone as my principal camera utilising several apps.

I have several concerns, the first is as follows.

I presently use keywords in Classic. My library is based on a folder structure inherited from prior to starting with LR. When I gained sufficient confidence in key wording, I permitted LR to use its folder dating method.  I have approx. 68k images taking up 85GB on a 1TB external HD. I hope that makes sense.  

If there is no key wording in CC how do I find all the pictures I have taken over the years and hopefully in the future, in Venice, for example, once I have transferred my library to CC?

I am sure I will have other questions, but this is central to any decision to make the change.

Thank you,

John