I had asked the same question when I had joined this space and looking for some guidance.
Everyone will provide you with some advice. Hear them out, then shortlist 3-4 coins. DO YOU OWN RESEARCH on those 3-4 coins. Its your hard earned money.
some general advice:
1. Dont put all you money in only 1 coin.
2. build a portfolio of 3-4 coins. out of that atleast1 should be a stable, top coin like BTC, ETH, LTC, etc.
3. The others can be coins that are priced between 1 - 100$ , 1Cent - 1$, and 1 less than a Cent.
4. Long term in crypto would mean different for different people.
5. Do not think that you will buy and hold and forget for a long time.
All the best.