Learn Hardcore Indonesian: Pemandu kami menjelaskan syarat keselamatan sebelum kami mulai mendaki. - Our guide explains the safety requirements before we start climbing.

kami excludes the person you’re speaking to (“we but not you”).
kita includes the person you’re speaking to (“we and you”).
In pemandu kami, the guide belongs to our group (excluding the listener). If you said pemandu kita, it would mean the guide belongs to a group that includes the listener.

How does the verb menjelaskan work? What is its root and how does the meN- prefix function here?

Root word: jelas (clear).
Prefix meN- turns adjectives or nouns into transitive verbs: menjelaskan = “to make clear” or “to explain.”
Because jelas starts with j, the nasal consonant in meN- stays n, giving menjelaskan.
It’s a transitive verb, so it takes a direct object (here, syarat keselamatan).

What does syarat keselamatan literally mean? Could it be translated differently?

syarat = requirement, condition, term
keselamatan = safety
Literally “safety requirements/conditions.”
Depending on context, you might also see it as “safety instructions,” “safety rules,” or “safety terms.”

Why does kami appear twice, and what are the functions of each occurrence?

1) pemandu kami = our guide (here kami is a possessive pronoun).
2) sebelum kami mulai mendaki = before we started climbing (here kami is the subject pronoun “we”).

How does sebelum work to connect the ideas in this sentence?

sebelum means before.
It introduces a subordinate clause and must be followed by a full clause (subject + verb): sebelum kami mulai mendaki (“before we began climbing”).
You could shorten it to sebelum mendaki if the subject is clear, but adding kami makes it explicit.

Why is it mulai mendaki rather than mendaki mulai?

mulai is a verb meaning “to start.”
When you combine it with another verb, the pattern is mulai + [verb] (here mendaki).
mendaki mulai would be ungrammatical in standard Indonesian.

Can I invert the clauses and say “Sebelum kami mulai mendaki, pemandu kami menjelaskan syarat keselamatan”?

Yes. Indonesian allows you to front the time-clause for emphasis. Just add a comma:
“Sebelum kami mulai mendaki, pemandu kami menjelaskan syarat keselamatan.”

Could menjelaskan be replaced by menerangkan in this context?

Yes. menerangkan also means “to explain” or “to clarify.”

Pemandu kami menerangkan syarat keselamatan sebelum kami mulai mendaki
Both verbs are correct; menjelaskan is slightly more common in formal instructions.

Should there be a preposition like kepada before kami to mark the indirect object of menjelaskan?

In Indonesian, transitive verbs like menjelaskan can take a direct object (syarat keselamatan) and an optional indirect object (kepada kami).
Here the indirect object is implicit because it’s clear who’s being addressed.
If you want to be explicit, you can say:
Pemandu kami menjelaskan syarat keselamatan kepada kami sebelum kami mulai mendaki.