Wij versieren de feestlocatie voordat we proosten.

Yes, wij and we both mean we.

The difference is mainly stress and emphasis:

• wij = the stressed form
• we = the unstressed form

So Wij versieren de feestlocatie can sound a bit more emphatic, like we are decorating the party venue.

In many everyday sentences, Dutch speakers prefer we in normal speech:

• We versieren de feestlocatie voordat we proosten.

Using wij is not wrong at all; it can just sound a little more deliberate or contrastive.

Here, versieren means to decorate.

So Wij versieren de feestlocatie means We decorate the party venue.

Be careful: versieren can also mean to charm, to flirt with, or to pick someone up in other contexts. But in this sentence, because the object is de feestlocatie, the meaning is clearly decorate.

Feestlocatie means party venue or event venue.

Dutch often forms compound nouns by writing them as one word.
So:

• feest = party
• locatie = location/venue

Together:

• feestlocatie = party venue

This is very common in Dutch. English often uses two words where Dutch uses one compound word.

Because the main noun here is locatie, and locatie is a de-word.

In Dutch compounds, the article usually depends on the last part of the compound, which is the main noun.

So:

• de locatie
• therefore de feestlocatie

That is why it is:

• de feestlocatie

and not:

• het feestlocatie

Voordat means before.

It introduces a clause telling you that one action happens earlier than another:

• Wij versieren de feestlocatie voordat we proosten.
• We decorate the party venue before we make a toast.

So the decorating happens first, and the toasting happens after that.

Because voordat introduces a subordinate clause.

In Dutch subordinate clauses, the verb usually goes toward the end of the clause.

So:

• voordat we proosten

is correct.

With only a subject and a verb, it may look similar to English, but the rule is still that subordinate clauses have different word order from main clauses.

Compare:

• Main clause: We proosten.
• Subordinate clause: voordat we proosten

If the clause were longer, the difference would be easier to see:

• voordat we samen proosten
• voordat we het glas heffen

It is in the present tense:

• wij versieren
• we proosten

Dutch uses the present tense not only for things happening now, but also for:

• habits
• general truths
• planned future actions

So this sentence could mean:

• something people usually do before a toast, or
• something they are about to do at an upcoming event

That is very normal in Dutch.

Yes, absolutely.

That version is also correct:

• Voordat we proosten, versieren we de feestlocatie.

When the sentence starts with the voordat-clause, the main clause follows with inversion:

• not ... wij versieren
• but ... versieren we

That is a very important Dutch word-order pattern:

• Wij versieren de feestlocatie voordat we proosten.
• Voordat we proosten, versieren we de feestlocatie.

Both mean the same thing, but the second version puts more focus on the time relationship.

Proosten means to make a toast or to toast, usually by raising glasses and saying something like Cheers!

It is often used on its own:

• We proosten. = We make a toast / We toast.

You can also say what you are toasting to with op:

• We proosten op het bruidspaar. = We toast the bride and groom.
• We proosten op het nieuwe jaar. = We toast the new year.

So in your sentence, we proosten simply means that the people will have a toast.

Yes, versieren is a regular verb.

Its infinitive is:

• versieren

Present tense:

• ik versier
• jij versiert
• hij/zij/het versiert
• wij/we versieren
• jullie versieren
• zij/ze versieren

So in the sentence:

• Wij versieren de feestlocatie the form versieren matches the subject wij/we.

Yes, proosten is also regular.

Present tense:

• ik proost
• jij proost / proost jij
• hij/zij/het proost
• wij/we proosten
• jullie proosten
• zij/ze proosten

So:

• we proosten

is the correct form for we.

Yes, it is natural and correct.

A very everyday version would probably be:

• We versieren de feestlocatie voordat we proosten.

That sounds smooth and normal.

Using wij instead of we makes it a bit more emphatic or slightly more formal in tone, but it is still perfectly natural.