The Two Main Paths
There are two main approaches to learning a language, output and input. Output refers to speaking and writing. Input refers to listening and reading. Which method you use, depends on your goals and personality. Personally, I prefer input methods as they are less stressful and are more a suited to my personality. They also lead to a high level of speaking fluency, but it might take longer to notice your progress.
Proponents of language approaches tend to be highly critical of other people's approaches, so I've included a couple of non-dogmatic videos discussing different approaches.
Getting Started with Comprehensible Input
Comprehensible input or content-based approaches involve a lot of listening and reading. Ideally, the content should be just a little harder than your current level. For the sake of pronunciation, start with more listening than reading or by listening to everything that you read. Check out the next video or links for more information.
Here are a few excellent programs that focus on making content comprehensible:
Language Reactor - see below (Desktop only - Chrome or Edge)
Smartbook: This is an android app that makes it easy to read and listen to eBooks in a foreign language. (Android only)
LingQ is a feature rich paid app designed to help you track your progress while using content from the across the web. (Desktop/Android/IOS)
Language Crush: If LingQ doesn't have your target language or if you are on a tight budget, LanguageCrush is a great alternative. (Desktop/Android/IOS)
Language Reactor is the best free program that I've found for learning languages. You can turn any Netflix or YouTube video with subtitles into an English lesson. There are some paid features that are good and help support the developer, but the free version is very functional.
It is an extension that you install in Chrome or Edge. Unfortunately, most mobile browsers don't support extensions, so you'll need to use it on a PC or Mac. If you have a tablet, you can try the Kiwi browser to use some of its features.