had better; it'd be better to; should~
Advises that one option is better than another; used for recommendations or warnings.
When you want to say 'had better' or 'it would be better to,' use the past tense of the verb before ほうがいい. This is common in everyday advice. For example, if someone is sick, you say 早く寝たほうがいいです (You'd better sleep early). The past form here is not about time; it's a set pattern.
You can also use this with nouns and adjectives. With a noun, add の (e.g., 医者のほうがいい). With a な-adjective, add な (e.g., 静かなほうがいい). With an い-adjective, use the past form (e.g., 安い -> 安かったほうがいい).
This pattern often sounds like a strong suggestion or warning. If you want to make it softer, you can add と 思う (I think) or use かもしれません. But at N5, just know it's direct advice.
Remember that the negative form is ないほうがいい (had better not). For verbs, use the ない-form without い, then add ほうがいい (e.g., 行かない -> 行かないほうがいい).