If your plan is to hold your cryptos in the long term, it would be worth it to make an effort to find methods or wallets that allow you to protect your coins offline. Currently there are many options in this regard and it is not difficult to obtain them. And this is especially recommended in your case, as you only have plans to invest in three cryptos. When the idea is to hold many coins is more complicated and perhaps an exchange may seem more practical, but risky.