Does a brand-new bike bought online need a service before riding it? I bought a brand-new road bike from a website.

The bike was preassembled and delivered in a big box.

The only things I had do were:
 - remove the styrofoam wrappings
 - screw on the pedals
 - loosen/reposition/tighten the handle bar (when the bike was delivered, the handle-bar was rotated and hooked under the top-tube so it was more compact for shipping)
 - adjust the height of the saddle

I have ridden the bike.  The tyres were already inflated.  The gear shifting works fine.  The brakes work.  The wheels spin fine.

But I noticed a (very) slight rattling noise (as if from the chain).

I took my bike to a local bike shop.  The man there told me the bike needs a service and it would cost £50.  He claimed it would make the bike "safe" to ride, and if I had bought the bike from his shop (a physical shop instead of a website), it would be "put together properly".

The cost of £50 was a little more than what I expected.  This is a brand-new bike, after all.

So my question is: should I get this brand-new bike serviced before I ride it?

Or are there some simple things I can do myself?  I can of course tighten everything with an allen key.  I can also lubricate the chain
and sprockets (or do I need to that?  I read somewhere that brand-new bikes all have been lubricated in the factory before they're sold.)

What else must I check (either myself or by a bike shop)?

Is it a not a good idea to start riding the bike without getting it serviced first?

Thank you for your input.
I took the bike to another bike shop.

The man there adjusted my handle bar (apparently when I did it myself, it was not good enough, not straight or aligned).

Then he put the bike on a stand and checked gear shifting to all the gears.  It all worked fine.

He also pointed out the slight rattling noise I heard is caused by the chain rubbing against the front derailleur.  This is normal and can be corrected by "trimming".  This YouTube video explains "trimming" the front derailleur.

The man said the bike is fine to ride.  I asked him when I should get it serviced, he said: "in 3 to 6 months, depending on how much you ride."

He also said not to put any lubricant on the chain because the factory has already done that.

I was in the shop for 10 minutes and he didn't charge me anything, even though I was more than happy to pay him for his courteous and informative service.

Clearly this is the shop I'll take my bike to for the next service.

So to answer my own question, it's advisable to have a professional check out the bike before you ride it, unless you're experienced with bikes yourself.  You don't need a "service" per se.

Like with all new products, one should study the owner's manual before thinking there's something wrong with the product.  I should think the owner's manual discusses "trimming".