Hello
Where are you from? Don't worry about making mistakes, everyone makes mistakes and the more you practice the better you become, so you should't really worry. If you want to improve your speaking skills you can watch movies in their original language and talk to native speakers, but if the problem is also grammar, then you should also work on that. There's a website that I know called Books4Languages where you can find free online books to learn languages, I think that it's very useful because you can look for the language that you want (in this case English) and the level that you want and you can also do exercises. You can take a look at it if you want. There are also websites where you can talk with other people that are learning English, the only one I know is EnglishLD but I'm sure there are more. You should try