I completed the Japanese N2 deck and am practicing Japanese regularly now. However I heard that both Japanese and Korean are Altaic languages and have the same grammar. I wanted to test this out by learning the basic Hangul then reading Japanese and Korean text side-by-side. Does anyone have any idea where I can find a Japanese-Korean resource (like the news for example) so that I can find out whether I have the ability to learn Korean through Japanese?
Some scholars claim that Japanese and Korean are Altaic but there are aslo linguists who think that Japanese and Korean represent isolated languages which are not related genetically with any other language family. As for the language typology, Japanese and Korean have many in common.
Japanese and Korean definitely come in handy when learning the other. You can in many cases compare certain Korean grammar points (such as many particles) to their Japanese counterparts to make them easier to learn/remember. However, this is not the case across the board. Some of the grammar is different. Much of both of their vocabularies are borrowed from Chinese (same with Vietnamese) which makes them easier to learn once you learn a couple tricks to switch the Korean pronunciations of Sino-Korean (words from Chinese) to Japanese and vice-versa.
As the above poster mentioned, many theorize that they are related but it has not been proven. Their similarities may just be due to the thousands of years of contact and borrowing between the two languages. Currently there is not enough evidence to prove an indisputable link.
One thing you might want to do is find a Korean list that also shows the Chinese characters while you study the vocabulary. That way you can connect the Korean word to the Kanji in your mind when you are learning it. That should make learning Korean vocab much quicker. Once you learn which Kanji is which word in Korean you can even start beginning to predict what certain words will be before you learn them if they are from Chinese. Good luck with your studies!