Translation:I will meet him next week.
They just taught me one (mimasu) was to see and the other (aimasu) was to meet. Then they quick switch it around for the sentence? Its confusing when they are not consistant. I can go to see someone.. Which might or might not be to meet up with them. If i see my favorite actor in a movie did i meet them? Nopers. If i saw mom at the park.. Did i meet with her as well? Im not really being clear. Maybe i just saw her.. She/i was jogging.. So i just saw her. Maybe i was in the car driving by and i saw her there sitting on a park bench. For clarity, to see and to actually meet is two different things to me. Even in (US)english.
This is just the opposite with the music thing. In Japanese (and German, too, and possibly many languages), you "hear" music. In English, you listen to music, but you can also just hear music without actually listening. But for some reason, Doulingo does not accept the "I hear music" translation. Although both are the same in Japanese. 音楽を聞きます
It's possible to use both ～にあいます and ～とあいます。There is a slight difference between the two. ～にあいます is used more generally and means that you are visiting person ～. The person you are visiting does not have to go anywhere, you are visiting him/her. However, if you use ～とあいます, it carries the nuance of a more formal meeting in a neutral location. In other words, you are both going somewhere for the meeting.
に is used in this case for 'to' に is used for meeting someone, time, and places. Literally "Him to meet." で is very similar, but they have differences. Look up some stuff online. https://www.wasabi-jpn.com/japanese-grammar/japanese-particle-ni-clear-up-all-doubts-you-may-have/
Homophones exist in all languages.
For instance in English, "Well" can be a noun meaning a pit dug into the ground where water (or brine, oil, or sulfer, etc.) is collected: "Can you go to the WELL and fetch a bucket of water?"; or it can be the adverb form of "good": "How are you?" "I am doing WELL, thank you.".
Another in English is "orange"; am I talking about the color or the fruit? Now that I think about it, Spanish has a similar issue with "naranja".
This is actually the one thing that I like about Japanese Kanji; it's that they mitigate most of the ambiguity between same-sounding words
No. 会う is the dictionary form of "meet". There are many forms. 会った is the informal past form. 会わない is the informal negative form. 会います、会いたい are the formal and the "let's meet" form. Here, 会い isn't even a complete word, just one of the many verb stems of the verb which means "meet". 愛 means love. But 恋 means love, too (こい) and both words have a slightly different meaning. And to make it worse, 鯉 (こい) can also mean carp. You might have heard of that before. はしゃぐ恋は池の鯉 is actually a line of the first Ranma 1/2 OP song, which is a song full of homophones. There's also 1000 meanings for きょう, for example 今日 today or 恐 (something similar to evil) or 京 (a part of the names of both the old 京都 and new 東京 capital, meaning capital). But 愛 is not a homophone for 会う.