As die staproete wegdraai, sal ons saamstap.

In Afrikaans, as often introduces a subordinate clause meaning if or when. Context tells you which English translation fits best.

So in this sentence, as is not the comparison word from English as ... as. It is the conjunction that starts the first clause: As die staproete wegdraai.

Staproete is a compound noun:

• stap = walk
• roete = route

Together, staproete means something like walking route, trail, or footpath, depending on context.

Afrikaans makes compound nouns as one word very often, much like Dutch and German.

Because Afrikaans normally writes compound nouns as a single word.

So:

• stap + roete → staproete

This is very common in Afrikaans. English often uses two words where Afrikaans prefers one compound.

It is singular.

The basic noun is roete = route. Its plural is roetes.

So:

• die staproete = the walking route / the trail
• die staproetes = the walking routes / the trails

Even though staproete ends in -e, it is still singular.

Wegdraai is a verb made up of:

• weg = away
• draai = turn

Together it means something like turn away, veer off, or bend away, depending on context.

With a route or trail, it usually describes the path changing direction and going off in another direction.

Because wegdraai is treated as a single verb in this position.

A useful comparison is:

• Main clause: Die staproete draai weg.
• Subordinate clause: as die staproete wegdraai

In a simple main clause, the parts may appear separated. In a subordinate clause introduced by as, the verb goes to the end, and the form appears together as wegdraai.

Because as introduces a subordinate clause, and in Afrikaans subordinate clauses the verb typically goes to the end.

So:

• As die staproete wegdraai

has this pattern:

• As
  • subject + rest + verb at the end

That is very normal Afrikaans word order.

Because the sentence begins with the subordinate clause As die staproete wegdraai, and that whole clause takes the first position in the sentence.

Afrikaans main clauses usually put the finite verb in the second position. So after that first clause, the finite verb sal comes next, before the subject ons:

• As die staproete wegdraai, sal ons saamstap.

If you put the main clause first, you get the more basic order:

• Ons sal saamstap as die staproete wegdraai.

Sal is an auxiliary verb. In sentences like this, it usually marks the future:

• Ons sal saamstap = We will walk together

So sal works much like English will.

Saamstap means walk together or go along together on foot.

It contains:

• saam = together
• stap = walk

So sal ons saamstap means we will walk together.

Often you may see both kinds of patterns in Afrikaans, depending on how the words function in the sentence.

For example:

• Ons stap saam. = We walk together.

Here saam behaves more like an adverb.

But saamstap is also used as a single verb meaning walk together / accompany on foot. In your sentence, saamstap is treated as that verb.

So the important thing for a learner is:

• Ons stap saam is a normal pattern.
• saamstap is also a normal verb form.

In Afrikaans, ons can mean both we and us. The sentence structure tells you which one it is.

Here it is the subject, so it means we:

• sal ons saamstap = we will walk together

Yes, the comma is standard here because the sentence starts with a subordinate clause:

• As die staproete wegdraai, sal ons saamstap.

That comma helps separate the opening as-clause from the main clause.

Like this:

• Die staproete draai weg. = the trail turns away
• Ons sal saamstap. = we will walk together

When the first clause becomes a subordinate clause after as, the verb moves to the end:

• As die staproete wegdraai ...

And because that clause comes first, the main clause shows inversion:

• ... sal ons saamstap.