En el camino encontramos una seta junto a otra piedra y mi madre dijo que no la tocáramos.

Yes. Encontramos can be either:

• present: we find
• preterite: we found

In this sentence, the context makes it clearly preterite:

• mi madre dijo = my mother said
• no la tocáramos = a past reported instruction

So the whole sentence is telling a past event, which is why encontramos is understood as we found.

Both are possible, but they are not exactly the same.

• en el camino = on the path / on the road
• por el camino = along the way / on the way

In this sentence, en el camino places the action physically on the path. It sounds like the mushroom and the stone were there on the path or while they were on it.

Also, camino is masculine, so it is el camino.

In Spain, seta is a very common word for mushroom, especially one growing in the wild.

• seta = mushroom
• hongo = fungus

Hongo is broader and more scientific. A native speaker in everyday conversation is very likely to say seta if they mean a mushroom you see outdoors.

Also, seta is feminine, which matters later for la.

Junto a means next to, beside, or right by.

So:

• una seta junto a otra piedra = a mushroom next to another stone

A very similar expression is al lado de:

• junto a otra piedra
• al lado de otra piedra

Both are natural. Junto a is just a bit more compact.

In Spanish, otro / otra already includes the idea of another, so you do not normally use un/una before it in this meaning.

So:

• otra piedra = another stone
• not una otra piedra

This is different from English, where another historically contains an + other, but in modern Spanish otra stands on its own.

Dijo que means said that.

It introduces reported speech or a reported idea:

• Mi madre dijo que no la tocáramos
  = My mother said that we shouldn’t touch it

Spanish often uses decir que to report what someone said, thought, ordered, suggested, etc., depending on the context.

Here, it is not just neutral reporting. Because what follows is no la tocáramos, it sounds like your mother gave an instruction or warning.

Tocáramos is the imperfect subjunctive of tocar.

It appears because after a past verb like dijo, Spanish often uses the subjunctive when reporting:

• commands
• wishes
• advice
• warnings
• things that are not simple facts

Here the idea is:

• My mother said that we should not touch it
• My mother told us not to touch it

That kind of reported instruction normally triggers the subjunctive.

By contrast:

• tocamos = we touched / we touch
• tocábamos = we were touching / used to touch

Neither fits the meaning of a reported warning.

Both structures are possible, but they are used differently.

In the original sentence:

• mi madre dijo que no la tocáramos

This is a full reported clause: my mother said that we shouldn’t touch it.

Another possible wording:

• mi madre dijo no tocarla
• mi madre nos dijo que no la tocáramos
• mi madre nos dijo no tocarla

However, dijo que no la tocáramos is very natural when reporting a negative instruction in a complete sentence.

Also, adding nos would make the target clearer:

• mi madre nos dijo que no la tocáramos

But Spanish often leaves nos out if it is obvious from context.

La refers to una seta.

That makes sense because:

• seta is feminine singular
• la is a feminine singular direct object pronoun

So:

• no la tocáramos = that we shouldn’t touch it
• literally, that we not touch her/it, but here of course it means it

Even though piedra is also feminine, the likely meaning is that the mother warned them not to touch the mushroom, not the stone. Context tells you which noun la points to.

Because here the verb is a finite verb form: tocáramos.

In Spanish, object pronouns usually go:

• before finite verbs
  
  • la tocáramos
• attached to infinitives, gerunds, and affirmative commands
  
  • tocarla
  • tocándola
  • tócala

So in this sentence, la tocáramos is the correct pattern.

Yes. Both are correct imperfect subjunctive forms:

• tocáramos
• tocásemos

In modern Spanish, both are grammatical and common. In many contexts, -ra forms like tocáramos are more frequent in everyday speech, but tocásemos would sound perfectly natural too.

So:

• mi madre dijo que no la tocáramos
• mi madre dijo que no la tocásemos

Both mean the same thing here.

Because una seta is a thing, not a specific person.

The personal a is used mainly with direct objects that are:

• people
• sometimes pets or personified beings
• specific animate beings

So:

• Encontramos una seta = correct
• not Encontramos a una seta

But you would say:

• Encontramos a mi madre

because mi madre is a person.

Both are possible.

• mi madre dijo que no la tocáramos = natural, especially when context already makes it obvious who she was speaking to
• mi madre nos dijo que no la tocáramos = more explicit: my mother told us not to touch it

Adding nos makes the indirect object clear. Leaving it out is normal if it is already understood.

The accent shows the correct stress.

Without the written accent, the word would not follow normal stress rules for that verb form. Spanish uses accent marks to show pronunciation and sometimes to distinguish forms clearly.

So:

• tocáramos = correct spelling

It comes from the verb tocar, and the accent helps mark the stress on cá.

Yes, that is a very literal way to see the structure:

• dijo que no la tocáramos
• literally: said that we not touch it

But natural English usually changes that into:

• said that we shouldn’t touch it
• told us not to touch it

This is a good example of where Spanish uses a subjunctive clause and English prefers a different structure.