The questions everyone choosing a name asks, answered with the rule in hand and the source linked. This is not legal advice: it is public information, dated, so you can check it yourself.
The figures below are official fees, not a quote. An attorney's professional fees are separate, and it is better that they stay separate.
Searching the name on Google and seeing whether the .com is free is what everyone does. It is also what lets through the problems that cost money later.
It is the idea that explains almost everything that looks contradictory about trade marks, starting with why your name can be taken and available at once.
An opposition is not the office refusing you. It is a third party asking the office to refuse you, which is a different problem with different exits.
The registry said the name was available, so the name is yours. That inference is wrong, and it is the most expensive mistake of the whole incorporation process.