There is a method of buying bitcoin that is called DCA which is very good for a beginner. The DCA method allow someone to buy with small amount of money but at a regular interval like weekly or monthly. The amount you will need to purchase will be small compare to your total income so that your mind will not be in the investment and you must ensure that the money you are investing into bitcoin is not what you will use for your basic needs like food, shelter, utility and others. Read about the DCA method and start applying it consistently and you will be achieving something significant at the end of the day.