I will advice you to invest in bitcoin. Do not be disappointed if you invest and you see any decrement, you should not sell but continue to invest. We all still know that it is definitely coming that bitcoin will reach a very high price again.
If you want to invest on altcoins, you need to be careful because many of them have increased this time, any little fall on bitcoin will be a great fall on altcoins. Do more reach if you want to invest on altcoins, but I will advice you to invest in bitcoin.
Undoubtedly bitcoin is the best crypto currency to invest in, it stands at the very top alone, and there's a reason that it is like that. It is the first crypto to be created, and altcoins that followed after it, all modeled after it in one way or another. It has far more investors than other crypto coins, therefore it's relevance in the crypto market is far more assured than any altcoins.
If you want high profitability on the shortest term, bitcoin might not guarantee you this, except it's bull run season, but altcoins can be your best option. That is if OP is able to do his homework and choose a credible altcoins, that can be profitable and not fade away with his investment fund.
I'll personally advice him to choose a top altcoin like ethereum, which has a strong market structure like bitcoin. With an altcoin like that, you're sure that it will remain relevant in the crypto market, for a very very long time. Then do more research before buying into new developed altcoins, because of scam.