I'd like help

[Kebab]

Is there an easier way to memorize all the past tense that you need to use "Je suis" instead of "J'ai" for? C'est trop difficile!!!

Devenir
Revinir
Monter
Rentrer
Sortir
Venir
Arriver
Naitre (Someone correct me on this one)
Descendre
Entre
Rester
Tomber
Returner
Aller
Mourir
Partir
Passer

[Twitch]

Well Je suis is the verb Être (to be) and J'ai is the verb Avoir (to have). So you would just need to use the one that makes the most sense. Does it make more sense saying I am (Je suis), or I have (J'ai) in the situation. Then to make sure you can always use a good grammar checking program. J'ai is more popular, but for ones like mourir you would not say J'ai mort (I have dead) but Je suis mort (I am dead). On that note would you ever say 'I have died' in French?

[aFrenchie]

Quite hard to help you there! Yet another difficulty (like nouns' genders) for English speakers indeed, since all past tenses are used with "to have" for you (and yet another thing that makes English easy :D)
Native French know if it's "être" or "avoir" for all verbs before they can even read or write. It just sounds unnatural if you mix up the auxiliary, so you can't do the mistake :)
Twitch's trick could be helpful indeed, still there are exceptions, when a verb can be used with both auxiliaries, in two different meanings of course (argh :))

[garçoncanadien]

If the verb has to do with some action relating to your whole body - use être as the auxiliaire. If the verb is reflexive, use être without exception. If the verb does not have to do with some action relating to your whole body, use avoir. I was taught this rule in primary school and it covered ~ 90% of the cases :)

[Cooney]

Oi, it's the bloody House of Être! How I loathe and fear it.

When we were learning it back in the day, we actually had a little picture of a house with arrows indicating actions associated with all those verbs (tomber - falling from a window, descendre - going down the steps, etc), but mostly we had to brute force memorize it. I'm far from solid on all of them today.

[Twitch]

If the verb has to do with some action relating to your whole body - use être as the auxiliaire. If the verb is reflexive, use être without exception. If the verb does not have to do with some action relating to your whole body, use avoir. I was taught this rule in primary school and it covered ~ 90% of the cases :)
I remember being told the same thing, just couldn't quite figure out how to best explain it. But like garçoncanadien says it does work most of the time. :)