Dalhin mo ang lapis sa silid-aralan bago magsimula ang gawain.

Dalhin is the object-focused form of the root dala. It is used when the thing being brought is the ang-marked topic, which here is ang lapis.

If you used magdala, you would normally build the sentence differently, for example: Magdala ka ng lapis... In that version, the doer is in focus, and lapis would usually be marked with ng, not ang.

Yes. In this sentence, dalhin mo functions as a command: bring it or you bring it.

Filipino often uses a verb form like this for commands. If you want to sound more polite, you could add po, as in Dalhin mo po ang lapis...

Mo is the genitive form meaning you / your, and in this pattern it marks the doer of the action.

Short pronouns like mo, ko, ka often come after the first word or predicate in the sentence. So Dalhin mo is the normal order, not Mo dalhin.

Because ang does not simply mark the English-style subject. In Filipino, ang marks the topic or focus of the clause.

With the object-focused verb dalhin, the thing affected by the action gets marked with ang. So ang lapis is the focused noun, even though in English it would be the object of bring.

Not exactly. In many translations, ang lapis may become the pencil, but ang is not just a direct equivalent of the.

Its main job is grammatical: it marks the topic/focus of the clause. Sometimes that lines up with English the, but not always.

Sa is a location or direction marker. It can mean to, at, in, on, depending on context.

Here it shows movement toward a place, so sa silid-aralan means to the classroom.

Silid-aralan is a compound word. Silid means room, and aralan comes from aral, related to study / learning.

So literally it is something like study room, but the normal meaning is classroom. Hyphenation is common in Filipino compound words like this.

Magsimula ang gawain means the activity begins or the activity starts. The activity itself is the one starting.

Simulan ang gawain means start the activity, which implies someone is doing the starting. So the original sentence means before the activity begins, not specifically before someone starts the activity.

Magsimula means to begin / to start. In this sentence it is used in a way that makes ang gawain the one that begins.

So magsimula ang gawain is literally the activity starts.

Gawain comes from gawa, meaning do / make. It often means task, activity, exercise, assignment, or thing to be done.

In a classroom sentence like this, gawain usually means a class activity or task.

Verb-first or predicate-first order is very common in Filipino. So starting with Dalhin is normal.

That is especially natural in commands, where the action usually comes first: Dalhin mo ang lapis...

It can also mean take or carry, depending on context. Filipino does not always force the same bring vs. take distinction that English does.

In this sentence, the context makes bring the most natural translation.