buying bitcoin and holding it is the safest possible bitcoin related investment. the only risk is the price that may go down. but if you hold it for the long term then it is a solid investment.
It is not a bad thing to invest in Bitcoin today but of you are serious about making money with Bitcoin you should buy more then one Bitcoin.
I am sure that if you buy only one now that you will regret it.
Investing is nice if you are for sure that you can earn money with it and Bitcoin is a currency so you never know what will happen with the value in the future.
But it is not that worst if the value is low you have just to take the right moment when you are going to sell it.
And it can takes indeed a long time until the value will be more worth but just wait and have the patience for it.
Yes if you want to earn huge profit then I think you need to wait longer and your patience will be surely tasted, so don't expect that bitcoin price will reach to the moon overnight.