The first thing you need to be able to do is distinguish between katakana and hiragana.
In most dictionaries, it is rather standard to use katakana to show the on'yomi (or, Chinese derived pronunciation) of the character. Hiragana is used to show the kun'yomi (native Japanese pronunciation). Characters can have multiple on'yomi and multiple kun'yomi; it all depends on the history of the character and its usage. While one can formulate some general rules of usage, it's mostly through context and familiarity that you'll understand which pronunciation is used or expected---and, then there are odd-ball cases where all rules fly out the window.
The コウ that you see there is the on'yomi for 好, which is the pronunciation used in many, but not all, compounds (it depends on the character). So, in 好機, you'll use the on'yomi to get こうき. Or in 好奇心 to read this as こうきしん. Not all characters have an on'yomi, but most do.
In the hiragana reading, the period marks where the okurigana should begin (I say should because it can depend on who and when something was published different rules may apply). Okurigana are ideally aide the reader in determining not only the inflection (such as for verbs) but distinguishing when which kun'yomi is intended. For example:
この.む --> 好む
Or, if you see,
お好みやき
The み is the inflected okurigana and tells you that this is read
おこのみやき
There are some words where you have to guess completely by context, e.g. 行く has amongs other readings the kun'yomi い.く and おこな.う which would be ok but the past tenses are いった and おこなった respectively, both written usually as 行った.
So while
大阪で行{おこな}った大会
obviously means tournament that took place in Osaka and not tournament, that walked in Osaka
大阪に行{い}った人
is a person that went to Osaka。