Now the question is, should I buy BTC (currently I don't have any BTC) or should I do DCA for ETH, SOL or DOT?
Short answer: stay on Bitcoin.
Long answer:
1. If you are not sure about a coin, then just stay away from it.
2. Altcoins are much riskier than Bitcoin.
3. The vast majority of altcoins don't survive or fall badly on long term, hence DCA may not make sense on them. Even ETH is expected to get in trouble after giving up PoW, but I didn't follow the story/drama much.
All in all, altcoins need you to be overly careful and probably overly lucky too, else you can easily end up in a loss.
Also, as said, if you want people advise you the altcoins, then maybe you should ask in Altcoin Discussion
PS. This is just my logic, not a financial advice; please do as you think with your money.