You will not lose or regret if you invest all in Bitcoin and this is absolutely your choice to make.

But as a long-time investor, my candid advice for you is to diversify your portfolio, this is not because Bitcoin is not safe or wouldn't earn you money but to make more money. This advice is wise as Bitcoin is not the only cryptocurrency. Many might advise you to do Bitcoin! Bitcoin!! Bitcoin!!! but they are investing in altcoins too, so you need to be wise, some people are fake.

Just do your research if you would invest in altcoins, follow the right projects and you won't regret it. You might want to invest 30% or more in Bitcoin and the rest in altcoins, the choice is yours.