Im Schrank stehen noch zwei Dosen Bohnen, aber keine Packung Reis mehr.

German main clauses use the verb-second rule: the finite verb must come in the second position.

So in:

Im Schrank stehen noch zwei Dosen Bohnen ...

the first position is taken by Im Schrank, and the verb stehen comes next. The subject then follows:

• Im Schrank = first position
• stehen = verb in second position
• noch zwei Dosen Bohnen = subject

If you started with the subject instead, that would also be possible:

Noch zwei Dosen Bohnen stehen im Schrank ...

Both are grammatical, but the original version emphasizes where the items are.

Because this sentence describes location, not movement.

• im Schrank = in dem Schrank = in the cupboard/closet → dative
• in den Schrank = into the cupboard/closet → accusative

German uses:

• dative for where something is
• accusative for where something is going

Here, the beans and rice are already inside the cupboard, so German uses im Schrank.

German often uses different verbs for the position of objects:

• stehen = stand
• liegen = lie
• hängen = hang

For containers like cans, bottles, boxes, and packages, German often uses stehen if they are thought of as being upright.

So:

• Die Dosen stehen im Schrank.
• Die Flasche steht auf dem Tisch.

English usually just says there are or there is, but German often chooses a more specific positional verb.

Because the subject is plural:

zwei Dosen Bohnen = two cans of beans

Since there are two cans, the verb must be plural:

• eine Dose → steht
• zwei Dosen → stehen

So stehen agrees with the plural subject.

Here noch means something like still or yet in the sense of there are still some left.

So:

noch zwei Dosen Bohnen
= two cans of beans still remain / are still there

It suggests that the beans are still available.

In this sentence, mehr means any more / no longer.

So:

keine Packung Reis mehr
= no pack of rice any more

The combination kein/keine ... mehr is very common in German for saying that something is no longer there or not left anymore.

Compare:

• Es gibt noch Reis. = There is still rice.
• Es gibt keinen Reis mehr. = There is no rice left anymore.

In your sentence, noch contrasts with mehr:

• noch zwei Dosen Bohnen = there are still two cans of beans
• keine Packung Reis mehr = but no pack of rice anymore

In German, quantity/container expressions often work without von, especially in everyday language.

So German normally says:

• eine Tasse Kaffee
• zwei Flaschen Wasser
• drei Kilo Äpfel
• zwei Dosen Bohnen

This is similar to English two cans of beans, but German often just puts the measured noun directly after the container noun.

von is possible in some contexts, but here it would sound less natural.

Because they behave differently as nouns.

• Bohnen is a countable plural noun: beans
• Reis is usually an uncountable mass noun: rice

So:

• zwei Dosen Bohnen = two cans of beans
• eine Packung Reis = a pack of rice

You count Dosen and Packung, not the rice itself.

After words that describe a container, amount, or unit, German often leaves out the article before the substance or item inside.

So these are normal:

• eine Packung Reis
• zwei Dosen Bohnen
• eine Flasche Milch
• drei Kilo Kartoffeln

This works a lot like English:

• a pack of rice
• two cans of beans

German simply does not need an article there.

Keine Packung Reis is natural because it means not a single pack of rice.

German often uses the singular after kein/keine when referring to the absence of even one unit:

• keine Packung Reis
• kein Glas Wasser
• keine Flasche Saft

You could also hear keine Packungen Reis, but that sounds more like no packs of rice at all in a broader, more explicitly plural sense.

In this sentence, keine Packung Reis mehr is a very natural way to say there isn’t any pack of rice left.

They are in the nominative, because they are the things that stand in the cupboard.

Even though the verb comes before them, they are still the grammatical subject(s).

You can see this especially with keine Packung, where keine is the nominative feminine form matching die Packung.

Because aber connects two coordinated parts, and in German a comma is normally used before aber.

So:

Im Schrank stehen noch zwei Dosen Bohnen, aber keine Packung Reis mehr.

The second part leaves out the repeated verb steht/stehen because it is understood from the first part. This kind of omission is common.

You can think of it as roughly:

Im Schrank stehen noch zwei Dosen Bohnen, aber im Schrank steht keine Packung Reis mehr.

The full repetition is unnecessary, so German leaves it out.