Nobody speaks in kanji. You don't go English → Kanji → pronunciation.
If you don't know which word to use in a given sentence you use a dictionary which contains words and their meanings and uses, rather than looking up individual kanji readings. Ideally look for a dictionary meant for specifically beginners English→Japanese which shows you example sentences. This so you don't accidentally land on something obscure/slangy/archaic, which is an issue with some of the online dictionaries, and so that you can distinguish between which translation you need for e.g. "strawberry jam" and "traffic jam" and "jam session"
Words can be read with on-readings, kun-readings, mixed on/kun, or special readings which are none of the above. Common example: 今日 (today) is きょう. No relation to the kanji readings (there are historical reasons for this which are interesting but not necessary to learning the language)
人 by itself meaning "person" as in an individual human being is ひと. "this person" could be この人(hito)、この方(kata)、この人物(jinbutsu)、 こちら (not normally written with kanji) and probably some other phrasings that aren't coming to mind right now depending on circumstances.
"person" more generally could be all kinds of things depending on the context - e.g. "I saw it in person" or "He had stolen goods on his person" are not going to be 人.
Looking at this, you might wonder what the point is in learning the individual readings is. My personal opinion is that there isn't a point to learning them outside of words - you don't learn "hito, jin, nin", you learn words like 人 (hito), 日本人 (nihon jin) 三人 (san nin), or at least patterns ("jin" is always used when referring to nationalities, for example).
In some cases you will see readings listed for kanji that are actually relatively obscure. If you look at a list of readings for something like 生 you'll go dizzy but many of those readings are only used in one or two words. You don't need to learn every single possible reading the first time you come across a kanji.
It is useful to do some background reading about the construction of kanji. e.g. some elements are meaning hints, particularly those at left or bottom - 金 - metal. 銀、銅、鉱 all have 金 at left and are all related to "metal". Some elements are on-reading hints (e.g. 鉱 takes its on reading, こう, from the right hand side 広) - this doesn't always work but it's a common enough pattern that it's worth making a mental note of.