Leaving a domain parked at the domain registrar after registration won't hurt your eventual rankings in any way. Leaving a domain name with a default page at the domain registrar is very common. Pretty much all domains are in this state for at least a short amount of time. Many are left there for months or years.
Google doesn't want to index the site while it is parked at the domain registrar. Google says:
Parked domains are placeholder sites with little unique content, so Google doesn’t typically include them in search results.
However, once you put your own content on that domain, Google will crawl it again and immediately notice that it is no longer parked. At that point, Google will index your content just fine.
Googlebot has special code to help it identify parked domains. It will choose not to index the domain while parked, but no penalties are applied against the domain. You will be able to get it ranked again at any point you choose to unpark it.