Trading This is the easiest method by far as all you need is money and a website that allows you to buy BTC or other currencies Example- Bitrex
Many sites out there do a google search lol
So what you can do is buy and sell in short spurs or play the long term game There are websites that give you 1 coin for every coin you buy but the catch is you cannot cash out until one year has passed
You choose which one you want
2nd
Bitcoin mining
I am not too sure bout this one as ive never done any mining before However i do know that at times this is not actually viable as you will make a lost just based on electricity bills (Check the power consumption if you want to seriously consider this and check how much per ampere your bills are)
Basically you can buy a mining rig (Which are getting more expensive due to demand) and leave it on 24\7 to "mine"
All in all how you want to get bitcoin depends on which you fancy. Both ways need investments and both has risk this then goes to choice.
Hope you found this helpful maybe leave a love (took like 5 mins to write lol) :p