How to say "It's raining," "it was raining," etc.

I'm not very good at constructing sentences in Japanese, or just Japanese in general.
I use the website jisho.org as a dictionary, and I have found it very useful.
I want to be able to say "it's raining," "it was raining," etc. I would also like to be able to modify it, like "it rained a lot where I lived." I could probably improvise this, but it would most likely not make any sense...

For example: would "雨が降るにした" mean "It's going to rain..?"

I haven't really had formal lessons or anything like that, so I just try to pick stuff up as I go, so I don't really know how to do verb stuff.
I'm not even that good at English (on a technical level) either, so I don't know what all the tenses are.
So, I'm sorry 😔

(Oddly specific question because I'd like to use it to learn how verbs/"events" work in Japanese in general)

Hey imrunningoutofusernames (nice name btw) how u doin'?

To understand this, we need to go to the most basic sentence form of this example: "It rains" that in japanese is 雨が降る。

So, for "It's raining" is 雨が降っています and "It was raining" is 雨が降っていました。

You could perceive that only the end of the sentence changed. To turn into Progressive Form you need to turn the verb to the て form and this is something really helpful that we NEED to absorb. 

For "It rained a lot where i lived" is a lil bit more harsh. it turns 私が住んでいたところは、たくさん雨が降りました。

And for "It's going to rain", if ur looking to express something that looks like something is going to happen you use そうです。

It goes like this 雨が降りそうです。

I might think that this can help you in some way.