Bitcoin, ether are suggested for newbies who can build their portfolio perfectly without experiencing scam in the beginning. It is also good point to start analysing and collecting altcoins from now, thus you’ll get a lots of time to take final decision which altcoin you should buy. I can't suggest very low cap cause those are dangerous but litecoin, sandbox, cake, waves maybe okey as low cap. Check those
careful with coin like sandbox and coin like anything related with blockchain gaming, the fact that they are already down so significantly might seem interessting to you but honestly the era of blockchain gaming is done.
i would stick to your first recommendation that is bitcoin and ethereum, right now currently ethereum is having massive increase because most of project doesn't seem to get interested into deploying their coin in L2 or other blockchain anymore, ethereum become primary choice for deploying tokens and something like that.
its definitely suited for investment.