Sykkelverkstedet åpner nå.

Because Norwegian very often builds nouns as compounds.

sykkelverkstedet can be broken down like this:

• sykkel = bicycle
• verksted = workshop / repair shop
• -et = the definite ending

So the whole word means the bicycle repair shop. English often uses several words where Norwegian prefers one compound word.

In Norwegian, the is often added to the end of the noun instead of being a separate word in front.

So:

• et verksted = a workshop
• verkstedet = the workshop

The same pattern works in the compound:

• et sykkelverksted = a bicycle repair shop
• sykkelverkstedet = the bicycle repair shop

So there is no separate word for the here, because it is built into the noun.

Because the main noun here is verksted, and verksted is a neuter noun.

In Norwegian, the gender of the final part of a compound decides the gender of the whole compound. Since it is:

• et verksted

the compound is also neuter:

• et sykkelverksted
• sykkelverkstedet

If the head noun were a common-gender noun, you would normally see -en instead.

åpner is the present tense of the verb å åpne, which means to open.

A few useful forms are:

• å åpne = to open
• åpner = opens / is opening
• åpnet = opened

So Sykkelverkstedet åpner nå uses the present tense.

Because Norwegian usually does not need a special progressive form like English is opening.

The plain present tense often covers both ideas:

• åpner = opens
• åpner nå = is opening now / opens now

The word nå makes it clear that the action is happening at this moment, so the present tense sounds natural.

nå means now.

In this sentence, it comes after the verb:

• Sykkelverkstedet åpner nå.

That is a very natural, neutral word order.

But you can also move nå to the front for emphasis:

• Nå åpner sykkelverkstedet.

When nå comes first, the verb still has to stay in second position, which is a basic Norwegian main-clause rule.

Because this sentence is using the verb actively and intransitively: the shop opens.

Norwegian often says things like:

• Butikken åpner klokka ni.
• Døra åpner ikke.

That is normal.

åpnes would be a passive form, more like is opened or gets opened, and it would sound more formal or like the focus is on the action done to something rather than the simple event.

So for a business opening, åpner is the natural choice.

Yes, especially y and å.

• y in sykkel does not exist in normal English pronunciation. It is like saying ee while rounding your lips. If you know German or French, it is similar to ü or u.
• å in åpner is a broad o/aw sound, not like the English letter name A.

Also, Norwegian pronunciation varies by dialect, so the exact sound can differ a bit depending on the speaker. But those two vowels are the main things an English speaker will usually notice first.