Przed przeprowadzką mam jeszcze dużo do zrobienia: spakować książki, zabrać swoje rzeczy i zmienić adres.

Because przed usually requires the instrumental case when it means before in a time sense.

• basic form: przeprowadzka = move, relocation
• after przed: przeprowadzką

So:

• przed przeprowadzką = before the move

This is a very common pattern:

• przed obiadem = before dinner
• przed spotkaniem = before the meeting
• przed wyjazdem = before the trip

Przeprowadzka is a noun meaning a move or moving house / moving to a new place.

It comes from the verb przeprowadzać się / przeprowadzić się, which means to move house.

Examples:

• Mam przeprowadzkę w przyszłym tygodniu. = I’m moving next week.
• Po przeprowadzce będę mieszkać bliżej pracy. = After the move, I’ll live closer to work.

So in this sentence, przed przeprowadzką means before moving / before the move.

Yes, literally mam means I have, but in Polish the structure mam coś do zrobienia is very common and means:

• I have something to do
• I still need to do something

So:

• mam jeszcze dużo do zrobienia = I still have a lot to do

This is extremely natural Polish.

Other examples:

• Mam pracę do skończenia. = I have work to finish.
• Mam kilka maili do napisania. = I have a few emails to write.

Here jeszcze means still.

So:

• mam dużo do zrobienia = I have a lot to do
• mam jeszcze dużo do zrobienia = I still have a lot to do

Depending on context, jeszcze can also mean yet, more, or another, but in this sentence still is the best match.

Examples:

• Jeszcze pracuję. = I’m still working.
• Chcesz jeszcze kawy? = Do you want more coffee?
• Jeszcze nie wiem. = I don’t know yet.

Dużo do zrobienia literally means a lot to do.

It is built like this:

• dużo = a lot
• do = to / for
• zrobienia = doing, making, getting done

The phrase coś do zrobienia means something to do.

So:

• dużo do zrobienia = a lot to do
• mało do zrobienia = little to do
• nic do zrobienia = nothing to do

Examples:

• Mam coś do zrobienia. = I have something to do.
• Nie mam nic do zrobienia. = I have nothing to do.

After do in this kind of structure, Polish uses a verbal noun, not an infinitive.

So:

• correct: do zrobienia
• not correct: do robić

This pattern is very common:

• książka do przeczytania = a book to read
• obiad do zjedzenia = a meal to eat
• raport do napisania = a report to write

In your sentence, do zrobienia is the general idea of to get done, and then the colon introduces the specific tasks.

Because they are listing the things that need to be done.

After a phrase like mam dużo do zrobienia, Polish often gives the tasks as infinitives, similar to an English to-do list:

• spakować książki
• zabrać swoje rzeczy
• zmienić adres

This is a very natural way to list planned or necessary actions.

You could think of it like:

• I still have a lot to do: pack books, take my things, and change my address.

They are perfective because the sentence is about completing specific tasks before the move.

• spakować = to pack up, to finish packing
• zabrać = to take, to take along
• zmienić = to change

Perfective verbs often fit well in lists of tasks because each action is seen as a completed whole.

Compare:

• pakować = to be packing / to pack in general

• spakować = to pack completely

• zmieniać = to be changing / to change repeatedly
• zmienić = to change once, successfully

In a to-do list, Polish usually prefers the perfective form when the goal is completion.

The difference is mainly aspect.

• pakować = imperfective
  focuses on the process, repetition, or general action
• spakować = perfective
  focuses on finishing the action

Examples:

• Pakuję książki. = I’m packing books.
• Muszę spakować książki. = I need to pack the books up / finish packing the books.

In this sentence, spakować książki means the books need to be packed as a completed task before the move.

Swój is a reflexive possessive adjective. Polish often uses it when the owner is the same as the subject of the sentence.

Here the subject is implied as I, so:

• zabrać swoje rzeczy = to take my own things

Using swój is very common and often preferred in Polish.

Compare:

• Wziąłem swoje klucze. = I took my keys.
• Wziąłem moje klucze. = possible, but usually less natural unless you want special emphasis, contrast, or clarification

So swoje rzeczy is the most natural choice here.

Rzeczy means things, belongings, or stuff, depending on context.

Singular:

• rzecz = thing

Plural:

• rzeczy = things

In the context of moving house, swoje rzeczy usually means:

• your belongings
• your stuff
• your personal things

So zabrać swoje rzeczy means something like take my belongings.

Literally it means to change the address, but in real life it usually means something broader, depending on context:

• update your address officially
• change your address in documents or systems
• notify people or institutions of your new address

So during a move, zmienić adres can imply:

• changing your registered address
• updating your mailing address
• changing your address with the bank, office, school, etc.

Polish often uses this shorter phrasing without spelling out every detail.

Yes, very natural.

The first part gives the general statement:

• Przed przeprowadzką mam jeszcze dużo do zrobienia

Then the colon introduces the specific items on the list:

• spakować książki, zabrać swoje rzeczy i zmienić adres

This is just like English when you say:

• I still have a lot to do: pack books, take my things, and change my address.

Yes, Polish word order is fairly flexible, although some versions sound more natural than others.

The given sentence is very natural:

• Przed przeprowadzką mam jeszcze dużo do zrobienia...

You could also say:

• Mam jeszcze dużo do zrobienia przed przeprowadzką...

This version puts slightly more focus on I still have a lot to do, and then adds before the move.

Both are correct. The original version sounds nicely organized because it sets the time frame first: before the move.

Because Polish does not need to repeat that idea once it has already been established by mam jeszcze dużo do zrobienia.

That phrase already tells you these are tasks that remain to be done. After that, the infinitives can simply be listed.

So this is understood as:

• I still have a lot to do:
  • pack books
  • take my things
  • change my address

Polish often avoids repeating extra words when the meaning is already clear.