This is good advice. You are never going to walk into a good salary which you're targeting without experience or it being the type of dangerous work you're considering.
As for contract work (someone else mentioned this) day rates won't include any sort of compensation such as pension, holidays, insurance or medical cover. At 24 sadly you really need to start thinking about your pension.
At 24 I had a forced career change, I got lucky and was offered a position which was relatively poorly paid but as I had very limited experience of the role (hobby) however I saw the long game. Worked my socks off, put my hand up for any weekend work which would enable me to work alongside more experienced folks and it paid off.
I now work in a global team (only member outside of the Americas) on a salary AND compensation package I'm happy with and could never of earned in my first career choice.
I had a little bit of luck and worked very hard once my foot was firmly in the door.
Good luck.