So many options to buy Bitcoin, you can decide to buy directly through exchange like binance or Coinbase. You can also make use of the Bitcoin focused investment vehicle like a Bitcoin ETF or like Grayscale Bitcoin trust.
One thing you must know when taking a decision to invest in Bitcoin .It's highly speculative investment. That's why it's more advice able to invest the amount you are comfortable losing.as Bitcoin price go up and down this season by hundred of dollars.
As a newbie, who just want to start your bitcoin journey, it is better that you check your monthly income and see how much that you will be able to use to buy bitcoin frequently either weekly or monthly that will not affect your income so that you will be able to take care of your monthly expenses and also still have emergency funds for any urgent need that will not make you to sell your bitcoin when it is not of your will. You can use 10% for a start and if 10% is too much for you base on your little income, you can reduce it to 5%. This will enable you after investing for the first time, you can continue to grow your bitcoin portfolio bit by bit through regular NCA weekly or monthly or even quarterly.
You should also have a bitcoin target so that you can work toward reaching your bitcoin target with patient and discipline because you are on a long term investment. The reason why you should always DCA regular is to remove the fear that might come from the market as you can buy bitcoin at any price at that moment because you have budget a portion of your salary to regular buying of bitcoin. Then if you income increases, you can also increase the amount that you were using to DCA.
If you are the type that use to have bonuses or extra cash from your working place, you can be saving that funds somewhere and use it to prepare for the dip, so that if peradventure bitcoin price dips, you can take advantage of the opportunity and use that money to buy at the dip, while your regular DCA continues. An investment is not something that can bring good profit in a short term because the investment hasn't matured yet and that is why you must be on a long term investment to lower the risk in bitcoin and have good profit at the long run. I see short term investors as traders and they are the ones that will fall for the volatile nature of bitcoin and loss from the market because they feel that they can outsmart the market with their charts and technical analysis and when they make wrong decisions and the market goes the opposite side, they end up in regrets. Buy and hodli bitcoin and increase your bitcoin portfolio with regular DCA method. Remember the size and timeline of your bitcoin portfolio is proportional to the profit you will get.