It depends entirely on your risk tolerance. If you can take a higher risk, I suggest you divide up 50% of the potential altcoin, and if you worry about losing your money, invest 70% in bitcoin, and the rest buy some of the mainstream coins, and the first ten coins in the market value are good. The project can also maintain a better growth.
For me if you having plan to invest on bitcoin first you do is monator the price so that you know the changes price of bitcoin and the best to buy if the price is low that time is good to purchase a bitcoin so that we can get a huge profit if the bitcoin price will recover so that is easy to invest on bitcoin but its risky.