If you mean slang as it is spoken in Spain, try Amazon Books, If you mean Spanglish, hang around Hispanic people. Here in the US, we have a mix of Spanish and English merged and it's not all slang . Just English interspersed with Spanish words.
Anyone can learn Spanish online through some good websites. The examples of such websites - www.studyspanish.com , www.spanishprograms.com and many more.
The word 'coochie' is internet slang for the female genitalia. You can learn more about this word online at the free dictionary or urban dictionary websites.
123 Spanish and Study Spanish are two places to learn Spanish for free. There is also Spanish dictionary that will teach most of the Spanish words and how to speak Spanish.
A spanish person
studyspanish.com
There are a number of reputable websites that offer to teach you Spanish in a fun and interesting way. Some of them are even free. One of the most popular and recognizable is Rosetta Stone. http://www.rosettastone.com/learn-Spanish
I wanted to learn basics of English grammar, where can I go online to learn free English conversation?
you can download the Duolingo mobile apps and can learn there free of cost.
There are multiple websites that available online dedicated to helping one learn English. These websites include Learn English Online Free, Talk English, and Free English Study. There are also free educational videos available on video sharing sites such as YouTube that can help one learn English.
There are many websites that will help you learn Spanish. Just 'Google' Spanish lessons. You can download free English/Spanish dictionaries, language lessons and even a verb conjugator to help you learn Spanish. Or, you can do what I did, find a group of Spanish-speaking people you can trust to teach you their language properly and just jump in and submerge yourself in their language and culture.
There are a lot of free materials that you can use, such as the Chinese learning websites, apps, and videos.
Duolingo and Memrise. I recommend duolingo.