First, To get a spell to work, you should will it, as in "I will it, so it shall be". Secondly, No not all spells work, For example, any spell that involves becoming something else, Mermaid, vampire, etc will not work. And you will usually be able to tell if a spell is legit or not simply by how it is written, If dey type liek dis, I'd just assume they won't work. Lastly, try something easy like a candle spell.
in my BOS I have a section called what every witch must know in it I have
1. meditation/ visualization
4. energy manipulation
I suggest learning them in order because each will help with the next for example mediation helps with learning how to stay focuses with grounding and grounding chakras help open the energy paths so you can manipulate energy and the guides protect you when you manipulate energy in spells after you learn all that I would say start casting spells that what I did.