Ens orientem i després clavem les piquetes per acampar.

Ens means ourselves/us here. The verb is orientar-se, a pronominal verb, so ens orientem means something like we orient ourselves or more naturally we get our bearings.

Without ens, orientem would usually mean we orient something else.

Catalan usually drops subject pronouns when the verb ending already shows who is doing the action.

• orientem = we orient ourselves
• clavem = we hammer in / we drive in

So nosaltres is not necessary unless you want extra emphasis or contrast:

• Nosaltres ens orientem, però ells no.
  We get our bearings, but they don’t.

In normal statements, Catalan object and reflexive pronouns usually go before the conjugated verb:

• ens orientem
• els veiem
• em llevo

You may see pronouns attached to the end of the verb in other structures, especially:

• infinitives: orientar-se
• gerunds: orientant-se
• affirmative commands: Orienteu-vos!

So in this sentence, ens orientem is the normal declarative order.

Catalan often uses the present tense for:

• routines
• instructions
• narrated sequences
• actions seen as the next steps in a process

So Ens orientem i després clavem les piquetes can sound natural even if English might prefer:

• We get our bearings and then drive in the pegs
• First we get oriented, then we hammer in the pegs
• sometimes even We’ll get our bearings and then..., depending on context

It does not have to mean strictly right now at this exact moment.

It comes from clavar, which literally can mean to nail, to stick in, or to drive in.

In a camping context, clavar les piquetes means:

• to hammer in the tent pegs
• to drive the stakes into the ground

So it is not about clapping or anything like that; it is a physical action of fixing the pegs into the ground.

Here piquetes means tent pegs or stakes.

In other contexts, piqueta can have other meanings, but in a sentence about camping, this is the natural interpretation.

So:

• clavar les piquetes = to hammer in the tent pegs

Catalan uses the definite article more often than English. In this sentence, les piquetes refers to the pegs involved in setting up camp, so the article sounds natural.

English often omits the article in more general expressions, but Catalan commonly keeps it:

• clavem les piquetes
• literally: we drive in the pegs

This does not necessarily mean some very specific pegs already mentioned earlier; it can simply be the expected pegs for the activity.

Because després on its own means afterwards / then.

In this sentence it links one action to the next:

• Ens orientem i després clavem les piquetes.
  We get our bearings and then we drive in the pegs.

You use després de before a noun or infinitive:

• després de sopar = after dinner / after eating
• després de caminar = after walking

So:

• després = afterwards / then
• després de + noun/infinitive = after ...

Per + infinitive often expresses purpose in Catalan.

So per acampar means:

• to camp
• in order to camp
• for camping

In this sentence, it explains the purpose of hammering in the pegs: you do that in order to camp.

Grammatically, yes, but it sounds awkward in English.

A more natural English rendering would be something like:

• We get our bearings and then hammer in the tent pegs to camp.
• We find our bearings and then drive in the stakes so we can camp.
• First we get oriented, then we hammer in the pegs for camping.

So the Catalan is straightforward, but the most natural English translation usually needs slightly different wording.