When deciding which cryptocurrencies to buy for both lomg term and short term, it's very important to take note of some factors that could impact how you make your profits over time.

Firstly is the exchange to use, where can you be purchasing and holding your crypto assets, how readily available is it. And good enough there are quite a lot of exchanges out there that offer different services, search for the ones that suits you most, also take into notice security measures, as this will count in the long run.

Secondly is the capital and the scope of investment; how much are you willing to invest, remember that cryptocurrency is a volatile asset that you should not invest more than you can afford to lose; after this is how long are you willing to invest your money, see the investment ss you're lending the project your money amd will be expecting it after some time.

Then which coins to invest; Look among the top ten cryptocurrencies by marketcap on coinmarketcap or coingecko then do your research over them and pick the one that has the most institutional backing amd support over time, so you could go for Bitcoin, Ether among many others because of their usecase and achievements over time. While doing this you can take some free online courses to help you manage your portfolio well, as it's very important as an investor to know about risk management