My first question is what is the difference between each engines what do they each contain for them to be different.
There are some differences in the physics between most engines; for example, ねころん's engine and many of the other engines on the wiki have a glitch where you full jump if you 1-frame in water. There are also different "standard" objects in each engine: some engines have gravity flippers, while others don't. You'd just have to look what each engine has already.
My second question is which is the best engine for me to start with to make a decent needle game unlike other trash ive seen on the wiki.
I personally like Lemon's engine the best, although yuuutu and Nikaple's engines are also perfectly fine from what I've seen.
My third question is what does a "standard" engine give me.
Once again, it depends on the engine; the few things that are in common among all engines are: the player sprite/object and anything that relates with the player (bow, bullet, etc.), spikes/cherries, save points, warps, and system objects that run the game. Pretty much everything found in the average fangame, especially needle, is found in an engine.