I am fluent in French, and I have taught both immersion and FSL. The only way to learn a language is to talk with people.
Early immersion is based on the "mother tongue" method. That means, you speak the language for quite a few years, before learning to read and write it, like children do with their first language. That is the only way to learn to "think" in the language. I have also studied German and Spanish, but used second language learning methods and I don't speak those languages well, although I can understand them, and read them.
I have studied Greek and Hebrew on line, but the purpose was to learn to read the Bible, not to speak the languages. Although, I confess the Greek I am taking now is actually making me talk it sometimes.
So my personal and professional opinion, is that there really are no on-line courses that are going to do the job. And neither will college, unless it is done by immersion. You need to find an adult speaking group, and maybe just study the vocabulary on your own. The big problem with French, is that it is highly idiosyncratic. Meaning the letters have different pronunciations, a lot of the last letters of words are silent, etc. So if you don't learn the words first, you will be constantly frustrated with trying to pronounce things the wrong way.
There are on-line university courses to learn French, but I still think it would be impossible without speaking it first. I worked on getting a French language proficiency certificate from Athabasca University, to upgrade my level of pay teaching. I never finished the last couple of courses, but I did learn a lot about grammar, vocabulary, etc. It was the French lit that really got me! Proust! Yikes! And I quit because I was just too sick with RA at the time to keep up.
Sorry if this is discouraging. I just want to urge you to find a class that uses immersion, until you are more or less fluent. Otherwise, you will never accomplish your goals.
