I think old project will be the best investment for you and you will never be disappointed with those projects because the best tokens always guarantee investors. Also if you want to hold for longer then definitely buy early top coins. If there are any profitable services offered by them, participate in them.
even though it is small, there is always an opportunity for early investors to make big profits from early stage projects, Moreover, when the new project has a launchpad on a large exchange like Binance, many investors will be busy buying the tokens offered by the project.
but for long-term investments, it's really not recommended to invest in new projects, it's better to focus on investing in projects that have been around for a long time and have a good reputation, you don't just think about momentary profits because long-term and safe profits are more important.