It's important to practice expressing yourself in your new language--saying what you want to say, outside of the shelter of the classroom. Do you like meeting new people? You might enjoy a language/conversation exchange, where you connect with someone (from around the world!) who speaks the language you're learning, and who is trying to learn the language you speak. The websites below can help you find a conversation partner.
If you decide to pursue a language exchange, please be cautious about sharing personal information, to keep your identity and your person safe. While some language exchanges turn into lifelong friendships, others fizzle out after the first meeting, so don't be disappointed if your exchange doesn't last. Be upfront with potential conversation partners about your expectations: How often/how long do you want to meet? How much time will you spend speaking in each language? Do you want your partner to correct your language? Do you want to choose topics or talk about whatever comes up?
To better understand grammar, it can be useful to look at real examples of how a particular structure or word is used. A "concordancer" is a tool that lets you search for a particular word, phrase or pattern, pulling out example sentences from a database of texts (which might be news articles, novels, speeches, etc.).
A search engine, like Google, can also be a quick, easy way to investigate questions like "What's the right way to say this?" Limit your results by domain to a country where the language is spoken (e.g., websites that end in ".es" for Spain). The more correct or natural wording will usually generate more search results.