Great question🙌🏻🙌🏻 Fortunately, you don't. They aren't necessary for learning Japanese, but they do help out sometimes.
The essential thing is to be able to recognize them by sight. They are the letters you'll be using, so you gotta get to know them (and to be honest they really aren't as scary as you may have heard. A lot of them even look really cool! Like 亜 or 回!)
Learning at least one reading (preferrably an on-reading) for each kanji is something I recommend, OR, alternatively learn one common word that uses that kanji. For example if you see 紹 (shou), you might think of it as, "the 紹shou in 紹介shoukai (introduction)"
There are some advantages to learning the readings, like that occasionally you can "guess" the readings of kanji to look words up easily. For example, when I see the word 正解 and want to look it up in the renshuu dictionary to see what it means, I have no way of typing it into the dictionary if I don't know the readings, so I'm stuck. This is a case where knowing those readings helps out a ton. A lot of times kanji have multiple readings though so it can be tricky, but since I know the first kanji has セイ、ショウ as its readings and the second one has カイ. I could try "せいかい" or "しょうかい" on my keyboard and see if that pulls it up. Sometimes it works, sometimes they surprise you with a different reading. It just saves some time once in a while
Aside from that if you just do the "learn a word" approach and you want to enter the kanji on your keyboard, you can type in the word you know that has that kanji in it and then backspace the rest of the word except for the kanji you wanted, its a little slow but it guarantees you can get that symbol on your keyboard without any guesswork. For the most part the readings are mainly only useful for looking words up in a dictionary or guessing how a word is read that you don't know - at least that's how it goes for me
Hopefully that rather lengthy explanation helps some (I talk too much I know lol), I think it also depends on the person too, if you have any other questions feel free to ask :)
