GUIDE

Kana

I don't want to lean japanese.

Good, you can find any traveler book with set phrases depending on the situation. They'll be witten in romaji, so no need to learn kana or kanji. Problem solved.

I want to learn japanese.

You first need to learn the kana, both hiragana and katakana. Check the resource page for learning practice those. You don't need to know them by heart, but at least be comfortable to start reading words.

Because Katakana is less common, it usually takes longer to be comfortable with them.

Bonus Time

I think it's safe to say you can learn kana within a week. You won't necesseraly know them by heart, by you should be able to read at slow speed.

So while you have this first week to get use to them, I suggest you use that time, to read this guide, and test the different options offered to you, and compare the different medthods and prices.

Maybe try to get use to Anki in the same time.
Think about checking if your local library has some resources that could help you in your study, try a few grammar textbook to check which one is the most appealing.