You should start with the problems you can solve.
If you go straight up this street and over the river, you will enter North America.
I’m sorry, but I have a prior engagement with my ex-boyfriend today, so I can’t meet up with you.
The kanji and the word are exactly the same. That means they share meanings as well.
Since this word is made up of a single kanji, it should use the kun'yomi reading. When learning the kanji, you didn't learn that reading, so here's a mnemonic to help you with this word:
When I think about the word "previous" I think of the beginning of a TV show where they say "previously on..." Let's go with that.
Previously on Lost (or some other show), the characters discovered a saw and a key(さき). Imagine all the characters in the TV show gathering around the suspicious items, wondering where they came from and what they're doing there.
You can differentiate this from 先ず (まず) because it doesn't have any hiragana on the end.