How do you make these predictions?

I was watching it like a hawk and the other day the price started falling fast so I decided to cash out.

Did I make a mistake?

Hi.

This is my first time posting on this board so I figured I'd introduce myself and ask a question that's probably already been asked and answered somewhere among the millions of threads here.

I recently within the past year downloaded Coinbase and over time bought 7 litecoins. Needless to say I'm glad I did. Of course I want to slam my head against the wall every time I watch the price
of Bitcoin go up to where it is today and wish I had a friggin time machine.  DOC!!!!  lol but anyway , I'm looking for advice on what other coin wallets are good for buying cryptocurrencies other that
the only 3 that coinbase supports. 

I am as new to this as I was to the internet in 2003 and that was back when I didn't even know how to copy and paste.   Yeah , I was that computer illiterate.

Thanks in advance.