Beg tidur aku di dalam khemah.

Malay often leaves out the verb to be when it links a thing to a place or description.

So:

• Beg tidur aku di dalam khemah.
• literally: My sleeping bag in the tent.
• natural English: My sleeping bag is in the tent.

This is completely normal in Malay. If you want, you can sometimes add ada to make the location more explicit:

• Beg tidur aku ada di dalam khemah.

That still means My sleeping bag is in the tent.

In Malay, possession is often shown by putting the possessor after the noun.

So:

• beg tidur = sleeping bag
• aku = I / me, but after a noun it can mean my

Therefore:

• beg tidur aku = my sleeping bag

This word order is very common in Malay:

• rumah saya = my house
• buku dia = his/her book
• kereta kami = our car

Aku is a more informal, personal way to say I / me / my.
Saya is more neutral and polite.

So:

• beg tidur aku = informal: my sleeping bag
• beg tidur saya = more polite/neutral: my sleeping bag

A native speaker might use aku with friends, family, or in casual speech. In formal situations, learners are usually taught saya first.

Di dalam means inside or in the inside of.

In this sentence:

• di = at / in / on (a preposition showing location)
• dalam = inside

So:

• di dalam khemah = inside the tent

Very often, Malay speakers also say just dalam khemah, especially in casual speech. But di dalam khemah is clear and perfectly correct.

Because this di is a preposition, not a verb prefix.

In Malay:

• di rumah = at home
• di dalam khemah = inside the tent

Here, di is written as a separate word.

But when di- is a passive verb prefix, it is attached:

• ditulis = written
• dibuka = opened

So in your sentence, di dalam must be written as two words.

Yes. The structure is very normal:

• Beg tidur aku = the thing being talked about
• di dalam khemah = where it is

So the pattern is basically:

• [noun phrase] + [location]

This is common in Malay:

• Buku saya di atas meja. = My book is on the table.
• Kasut dia di luar. = His/Her shoes are outside.

Yes, beg tidur is a normal and understandable way to say sleeping bag.

• beg is a loanword meaning bag
• tidur means sleep

Malay often forms noun phrases like this, where the second word describes the first:

• beg tidur = sleeping bag
• bilik tidur = bedroom (literally sleep room)
• topi keledar = helmet

So beg tidur is a straightforward compound noun.

Yes. That is probably the safest version for most learners.

Compare:

• Beg tidur aku di dalam khemah. = casual, informal
• Beg tidur saya di dalam khemah. = neutral, polite

Both are grammatically correct. The difference is mainly register.

Yes, in everyday speech many people would say that, and it sounds natural.

Compare:

• Beg tidur aku di dalam khemah.
• Beg tidur aku dalam khemah.

Both can mean My sleeping bag is in the tent.

The version with di dalam is a bit fuller and more explicit. The version with just dalam is often more conversational.

No. Malay does not usually use articles like a or the the way English does.

So khemah can mean:

• a tent
• the tent

The exact meaning depends on context.

In your sentence, English often translates it as the tent because the tent is probably already known from context. But Malay itself does not need a separate word for the here.