looking at the current market situation it seems difficult to make a profit on altcoins because currently the price of bitcoin is being corrected and this is also followed by most altcoins.
However, I also agree that bitcoin is the best, and it is better to create a new portfolio. However, if the OP's decision cannot be changed, then the answer to the question lies in popular altcoins that have low prices. Although this is also very risky. I would probably choose coins like ETH, BNB, Matic, and others. however, if the OP wants to make quick profits, he can try investing in new coins or new projects. However, the risks he had to face became increasingly higher.