Language learning is a long and often challenging process. In the past, learning a second language meant enrolling in expensive classes or buying hefty textbooks. But now, you can learn online with little or no cost. There are plenty of apps to study grammar and vocabulary in your desired language. There are also plenty more to practice your skills with a conversation partner. But if you really want to expand your vocabulary beyond a beginner level, you'll probably need to find other sources. Here's a quick start guide to learning new words and grammar points through reading and listening to the language.
First, you don't want to start from scratch by reading and listening to things that were written by and for native speakers. It's just not going to end well. When you're an absolute beginner in a language, you want to start small and simple. Begin by learning the very basics of the grammar, like subject-verb order and present vs past tense. Start off with a site dedicated to your desired language or with an app like Duolingo. These will give you the basics so you won't be overwhelmed when you start reading articles in the new language.
Second, pick your translation tool. Google Translate is probably the most universally known one, but there are literally hundreds of other free options available online. Maybe one made specifically for your target language would work better. Maybe not. (If you're feeling really ambitious, you might want to use a couple for cross-reference in case one translates something wrong.) Google Translate has a helpful Chrome extension you can install to translate words or phrases without leaving the page. There is also another free extension called ReadLang that does the same thing, but also creates digital flashcard decks from words that you look up.
Third, accept that you definitely won't understand everything. When you sit down to read anything in your target language (even if it's just a children's story), most of the words will be a mystery to you. That's okay. Try not to get discouraged. You don't have to master an entire article before you move on. In the beginning, it may be much easier to work on mastering just a paragraph or even a sentence. Set how much you want to read from an article and then move on.
Fourth, review and practice your vocabulary and grammar. Most of the time, this means flashcards. This is probably the fastest way to master individual vocabulary words. However, this technique is not that effective to practice or study grammar. For that, start with copying down some simple sentences to become familiar with the grammar structure. You can replace some of the words in the sentence to create new ones and still get the same basic meaning. For example, you might start with something like, “Oliver took the ball." You can replace the subject and direct object of the sentence to have a similar meaning. Something like, “Elisa took the plate." This is a very simple sentence, but this exercise can get more involved when you move on to more complex sentences. This is also a good way to reinforce the vocabulary you've learned.