Where is Tanaka? We usually say 田中さんは、どこにいますか？　 We dont say どこに田中さんがいますか?. The second one is grammatical OK, but, we say it in specific situations like looking at the photo in which 田中 must be, but cant find him. In this case どこにinformation is more important than the name of 田中, so we would use が.

It takes a couple of hours for foreigners to understand this grammar points. You shoud take lessons from a English speaking Japanese teacher.

咲くbloom, 咲かす　make something bloom. 咲かそう　this Ou conjugation is called Volitional form which means Let's do it.

この「に」は、助詞ですよね。には、場所を示すことがあります。　駅に来てください。ホテルにいます。などなど。文頭、これは、文の一番最初の場所なんです。

連絡させてもらうね　this phrase is normaly heard in this situation. A asked B to help A find a job at the company B is working for. B would say like 　求人の募集があったら、連絡させてもらうね。 B の気持ちは、「できれば、Aを助けてあげたい」です。 So, it's not appropriate for you to say 連絡させてもらうね　to the someone who will help you. Maybe you shoud say 連絡させて下さい　or 連絡しても良いですか?　or 連絡させてもらえますか?

Hello, Michelle. Reading each Katakana is not difficult. But, Katakana words are originally foreign words, mainly English. For example, ツアー　which is つあ－in Hiragana. Can you guess the meaning? It is tour in English. Katakana sound is sometimes very different to the original sounds. You will face it when you learn to read Katakana words. They will puzzle you. Anyway, Japanese From Zero can guide you for the time being.

I recommend you to take Genki book 1and 2 lessons to master our grammar step by step,and not to try to learn several particles at the same time.

You need to understand the basic concept of 敬語. In Genki book 2, there are 2 chapters for basic 敬語. If you need any help, please check my teacher profile.