Si vuelvo a acampar, traeré otra manta y más repelente.

In Spanish, after si meaning if, you normally use the present tense to talk about a real future possibility:

Si vuelvo a acampar, traeré... = If I go camping again, I’ll bring...

This pattern is very common:

• Si tengo tiempo, iré. = If I have time, I’ll go.
• Si llueve, nos quedaremos en casa. = If it rains, we’ll stay home.

So Spanish usually does present tense after si + future tense in the main clause, not future + future.

Volver a + infinitive means to do something again.

So:

• volver = to return / to come back
• volver a acampar = to go camping again

Examples:

• Vuelvo a leer el libro. = I read the book again.
• Volvió a llamar. = He/She called again.

In your sentence, si vuelvo a acampar means if I go camping again.

Because volver a + infinitive is a fixed structure in Spanish meaning to do something again.

So the a is required here:

• volver a intentar = to try again
• volver a ver = to see again
• volver a acampar = to go camping again

Without the a, the sentence would be incorrect.

Traeré is the first person singular future of traer:

• traeré = I will bring

The sentence is talking about what the speaker will do in a future situation, so the future tense fits naturally:

Si vuelvo a acampar, traeré otra manta y más repelente.

This is the same pattern as in English: If X happens, I’ll do Y.

Also, traer has an irregular future stem:

• infinitive: traer
• future stem: traer-
• but with an inserted d: traeré, traerás, traerá...

Actually the full future forms are:

• traeré
• traerás
• traerá
• traeremos
• traeréis
• traerán

Yes. In everyday Spanish, ir a + infinitive is very common for future meaning.

So you could say:

Si vuelvo a acampar, voy a traer otra manta y más repelente.

This also means If I go camping again, I’m going to bring another blanket and more repellent.

Both are correct:

• traeré = simple future, slightly more neutral or formal in tone
• voy a traer = very common in conversation

Because otro / otra already works like a determiner here, so you do not normally use un/una before it.

Correct:

• otra manta = another blanket
• otro día = another day
• otra vez = again / another time

Not normally:

• una otra manta

So otra already carries the idea of another by itself.

They mean different things.

• más repelente = more repellent
• otro repelente = another repellent / a different repellent

In your sentence, the speaker probably means they want a greater quantity of repellent, so más repelente is the natural choice.

Compare:

• Traeré más repelente. = I’ll bring more repellent.
• Traeré otro repelente. = I’ll bring another repellent / a different repellent product.

Because repelente here is being used as an uncountable substance, similar to water, milk, or sunscreen in English.

So:

• más repelente = more repellent

You are talking about more quantity of the substance, not one item.

If you wanted to talk about a specific product or container, you might use an article:

• otro repelente = another repellent product
• un repelente = a repellent
• más del repelente que compré = more of the repellent I bought

But in the original sentence, más repelente is the most natural form.

Yes. Acampar is the standard verb for to camp or to go camping.

Examples:

• Vamos a acampar este fin de semana. = We’re going camping this weekend.
• Me gusta acampar en la montaña. = I like camping in the mountains.

So volver a acampar is a very natural way to say to go camping again.

Yes, to some extent. The original order is the most neutral:

Si vuelvo a acampar, traeré otra manta y más repelente.

You could also put the main clause first:

Traeré otra manta y más repelente si vuelvo a acampar.

This means the same thing. The choice depends on what you want to emphasize first.

No. Spanish usually leaves out subject pronouns when the verb ending already makes the subject clear.

• vuelvo already tells us it means I return / I do again
• traeré already tells us it means I will bring

So yo is unnecessary here unless you want emphasis or contrast:

• Si yo vuelvo a acampar, traeré otra manta...

That might sound like: If I’m the one who goes camping again, I’ll bring another blanket...

But in a normal sentence, leaving out yo is more natural.

Because this sentence describes a real or possible future condition, and in that kind of si clause, Spanish normally uses the present indicative:

• Si vuelvo...
• Si tienes tiempo...
• Si hace buen tiempo...

The subjunctive is not normally used after si in this kind of structure.

Learners often expect subjunctive because the event is uncertain, but with si meaning if, Spanish usually does:

• si + present indicative
• main clause in future / present / imperative, depending on meaning

Example:

• Si vienes, te ayudo.
• Si vienes, te ayudaré.
• Si vienes, avísame.

So si vuelvo is exactly what you would expect here.