The easiest way to get a bitcoin is to buy it. Other than than that, there is no easy way to have a bitcoin. You apply signature campaign but it will take a long time to make your earnings to be a whole bitcoin. You have a lot of work to do before you can have a bitcoin.
Buying is not getting and buying is also not the easiest way as it needs investment and maybe not everyone can manage to do that.
That is the reason why there are ways to get bitcoins like signature campaigns or skill tasks etc by which people can earn bitcoins without investing anything.
You maybe could do some signature campaigns, I'm also doing this and its pretty profitable although it will go slow to gain one bitcoin, But I do not see any other methods plus this is without risks and faster than most other methods.