Unfortunately there is no single source that will teach you Chinook Jargon. I wish I could simply recommend a textbook or two like you could with other languages but that’s just not the case. Learning will be a journey that requires you to seek out many different resources. Here’s some to start you off though.
You will notice that I point out if something is ‘Northern Dialect’ (aka BC-Style Chinook) or ‘Southern Dialect’ (Grand Ronde Style). Do not feel like you have to use one or the other (they are quite similar), I just want you to be aware that there are differences. You should look at both styles.
Dictionary with texts if you have money for a book (Grand Ronde spelling) – Chinuk Wawa: Kakwa nsayka ulman-tilixam laska munk-kemteks nsayka
Dictionary as substitute for the above if you can’t buy it: Chinuk Wawa (Chinook Jargon) Etymologies
Dictionary for old style spellings: The Chinook Jargon and How to use it
Dictionary & lessons for Chinuk Pipa: Chinook Rudiments
Handy easy to search wordlists here
you can also search words on chinookjargon.com to get examples of them in actual use
Lessons for ‘Northern Dialect (BC-style)’ Chinook with accompanying learning papers: The Snass Sessions
Lessons for ‘Southern Dialect (Grand Ronde-style)’ Chinook: Lane Community College
www.chinookjargon.com – a blog run by linguist and Chinook Jargon expert Dr. David Robertson. The best source for Chinook Jargon content and to learn about Chinook Jargon. Take a look also at the “my writing” section if you would like more technical but very informative academic papers on Chinook.
bcchinookwawa.ca – a great source that includes recordings of elders talking chinook and the Snass Sessions with accompanying learning papers. You can reach out to them on their contact page to join the Snass sessions.
www.rjholton.com/ – informative work by Jim Holton
duanepasco.com – for Duane Pasco’s entertaining Chinook Jargon works.
Communities to learn and practice Chinook with
Historic Reading Material
Chinook Bible History (Chinuk Pipa)
Textbooks & Classroom Material
Grammar for Northern Dialect – Kamloops Chinuk Wawa, Chinuk Pipa, and the vitality of pidgins
Northern Dialect teaching papers – The Snass Sessions
Grammar for Southern Dialect – Chinuk-wawa learners’ grammar (Classroom versions) & Reference Version
History of the Grand Ronde people in Southern Chinuk Wawa – Shawash-ili7i tilixam 2017
Tips for Learning
Remember that you will never learn any language just by reading wordlists or dictionaries. Just like any language, to learn Chinook Jargon you need to use it; you need read a lot, listen to everything you can, write, and speak to get a good grasp of it. You need to do some every day, no matter how little. Just because Chinook Jargon is an easy language does not mean that the principles of language learning do not apply to it. I recommend you utilize every resource above and find a community to speak and write with.