I've x Have Been: Diferença entre frases

Hi,

I've a question, Can someone tell me what's the difference between the sentences below please...

I Fell ... [Eu caiu]
I've Fallen ... [Eu caí ou eu caiu?]
The same example with other verb
I eat ... [Eu como]
I've Ate ... [Eu como ou eu comi?]

Everytime I use "I've" I need to complete the sentence with the verb in past participle?

Now with I've Been

I've Fallen ...
I've been Falling ... [Eu tenho caído?]
I've Ate ...
I've been Eatting ... [Eu tenho comido?]

I've a problem to understand I've/I've Been, when you've to use the verb in past or not... Etc...

Thanks for helping.