Neither textbook is wrong, and it's important to learn both forms, but I would put my emphasis on studying the 요 form first, since you will be using this one more. Of course, the 니다 form is much simpler and doesn't take as much time to learn (making it also seem like a logical choice to study first so you can get going), but, hey, get the harder, more practical part out of the way first. Just as I would recommend an English learner study colloquial English before learning to talk like a news anchor (similar but not identical concept). Yes, 요 form is informal but still polite, making it a safe bet for a learner to use when speaking or writing. 니다 form is both formal and polite, but in most situations you'll run into (especially early on), this will be waaay too formal. You'll sound like such a noob :) Anyway, I would worry less about the names of things and more about the uses. Know when to use 요 form through examples. And likewise with 니다. 가다: 요 - 가요 니다 - 갑니다 하다: 요 - 해요 니다 - 합니다 보다: 요 - 봐요 니다 - 봅니다 Between each set, the meaning is exactly identical. The only difference is who you're talking TO (as opposed to about). Now, I'm not sure how much of an explanation on conjugating you're looking for...feel free to comment.

direct translations are 'do', 'go', 'look at' in the order but meaning can be different slightly depending on context. would you let me know whole sentences?

니다 form ... actually called "ㅂ니다/습니다" For regular verbs (including adjectives): Remove -다 to get the verb stem If the verb stem ends in a vowel, add ㅂ니다. OR If the verb stem ends in a consonant, add 습니다. That's it - very simple for regular verbs, like I said. ex) 1. 먹다 -> 먹 -> 먹습니다 2. 오다 -> 오 -> 옵니다 3. 마시다 -> 마시 -> 마십니다 4. 타다 -> 타 -> 탑니다 5. 자다 -> 자 -> 잡니다 6. 맞다 -> 맞 -> 맞습니다 For irregular verbs (incl adj): Normally 으 verbs would be considered irregular, but they conjugate just like above - by adding ㅂ니다. Same thing with 르 and ㅣ verbs. And ㅎ verbs. For verbs whose stems end in ㄹ, ㄹ gets deleted, leaving the stem ending in a vowel anyway. Then, continue the process and add ㅂ니다. 예) 1. 살다 -> 살 -> 살습니다 -> 사습니다 -> 삽니다 2. 날다 -> 날 -> 날습니다 -> 나습니다 -> 납니다 There is a rule that ㄹ gets deleted before the letter ㅅ, so that's why this is like this. This is the only irregular I can think of that is actually irregular in this form. Another example of this deletion rule: 1. 살다 -> 살 -> 사세요 (lives)

Here's an automatic conjugator: dongsa.net

Any luck with better understanding them? I suggest practicing using them yourself^^