Yes, you can stay with holding bitcoin and other common altcoins like ETH. That's all you need to do if you don't want to take risky investments by taking more altcoins in your stash.
There's really no need for you to be that type of investor that you'll hit every single new project that you see. It makes no sense because it's not that really needed at all.
If you seek assurance, then sticking with top coins such as Bitcoin and Ethereum will always be the best thing to do. Listening to FUD won't make you gain profit because not all new projects have potential and might only lead you to regrets in the end. Most of the new projects these days are struggling and not all of them could survive the bearish season.
Almost all new projects are just going to be dumped eventually and then there's no actual growth. At least a few of them survive but they're really rarely going to see a glimpse of success.
That's why investing in the stable ones and reputable projects like ETH and BTC will make you more stable and worry-free because they've been there for so long and are unlikely to rug pull. Well, technically bitcoin can't rug pull as there's no centralized authority holding most of its supply.