What is the best bike for me?
The best bike for you is one that you want to ride.
Your bike needs to be comfortable TO YOU which means the correct size.
It needs to suit your needs, whether that be commuting, training, shopping, adventure, offroad.
It needs to be affordable without breaking your budget, and leave enough spare cash for those extras like helmet, a bag, tools, spares, gloves, or whatever else you need.

The reason that a used bike is often suggested is because they are generally a lot cheaper than a new bike, plus in these C19 days the supply chain can be lumpy.
A used bike can let you ride the bike you think you want, and then you can buy another used bike of a style that grows on you later.  It is not uncommon for riders to want a squishy MTB to ride to work/school, and then realise how slow they are compared to something more road-oriented   (for example)
On the other hand, a new bike comes with some sort of warranty depending on your location.   Some people cannot stand the idea of riding a bike that someone else has ridden, so new is their only option.   That's okay too, but it costs more.
A bike that is bought with the best intentions but only gets a few rides before being stored, that's a ROPA (ridden once, put away) or a &quot;Garage Princess&quot;   If you have one of those in your extended family, then see if you can borrow it for a try.