I recently purchased 0.0045 Bitcoins which is still present in my trust wallet I believe with me owning a fraction of the worlds Bitcoin although a very tiny fraction in practical I am now a crypto currency investor in essence a Bitcoin investor
If you are a person who has just bought Bitcoin and kept it in your own trusted wallet, I will not consider you a Bitcoin investor as long as you don't use Bitcoin or invest it in a certain company. Because if you are only limited to buying and keeping in your wallet, you are not much different from Holders and also from traders who also try to save for a while before they sell it back to the market. So there's no need to consider yourself an investor if your effort is to save before selling again.
The OP is just starting, at least he already own Bitcoin which he can decide where to invest it. If he think it that way but still give a good effects let him be. Let's just educate them. He might become a trader than investor in what suits for him. And what you said is right holders and investor is different, holding Bitcoin and waiting for it to sell just to profit consider as trading. But if you're investing, you put your funds in a company for a long period of time or short for you to gain profits. Still congratulations to OP for taking a step in Bitcoin.