How don't you know how to acquired Bitcoin when you're basically saying investing, multiple times in your post. You can acquire Bitcoin by buying or working and getting paid in Bitcoin. Buying is the most popular since you can buy the amount you can afford and there isn't many employers that'll be willing to pay you in Bitcoin if it isn't a job relating to the cryptocurency industry. Many of us missed buying Bitcoin when it was cheaper but we don't have to make same mistakes against as the price will only keep increasing. It'll have some correction but for the long term, the price of Bitcoin will be higher than it currently is because of the law of demand and supply. The more Bitcoin gets popular and gains global acceptance, the higher the price of Bitcoin can climb because more investors will be introduced into the market while the supply of Bitcoin remains fix at 21 million.
Investing in Bitcoin isn't complicated, it's the easiest asset to Invest into and that's why we have a lot of amateur inventors in the market. If investing in Bitcoin was complicated Bitcoin won't have achieved all it has achieved in the short period of its existence. You can earn in various ways when you invest in Bitcoin like capital gains which you make when you buy, hodl then sell. You can also earn from trading Bitcoin but this isn't advisable if you don't have the experience on trading although if you're willing and dedicate some time to learning, you can learn how to trade and be making profits from doing so but the most profitable and reliable ways of earning form Bitcoin is buying and holding. In regards to the amount of money you can make from investing in Bitcoin, there's no fixed amount since investing in Bitcoin isn't a ponzi scheme that promise you a fixed ROI.