Can anyone give any tips to learning French faster?
They say the fastest way to learn a language is to live in a country where it's the primary language. Since that's not usually possible, try to bring that country to you as much and as often as possible.
The french news station, France 24, is constantly livestreaming on Youtube. You can also watch french versions of other things you might watch normally, but the advantage of the news is that the pronunciation is generally clearer. I've also changed the language of my TV and game console to french, and I made a reddit account and subscribed to several french subreddits.
Try to expose yourself to the language as often as possible.
The more you can practice, the better, and the more you can link practice to your everyday actions, the more memorable it is. As you go for a walk, count things, anything. Make a shopping list, run a defensive driving commentary in your head. I try to write in French everyday too - however simple, it helps with fluency and thinking in French rather than translating. Most of all - don't give up!
If there is a topic that you are really fond of, you can try to look for forums where people discuss about it in French. Ideally adults with some brains, because you will not learn much from adolescents with horrible grammar and SMS abbreviations. So you first read the comments, then you try to participate, using a dictionary, checking the expressions on WordReference. After months of this, you should have improved a lot.
The only way to excel in anything, is to expose and indulge your self into it as much as possible. This meaning watch Movies in French, go to French chat rooms so you can type in French some even let you speak if you have a mic. Read any thing you can get your hands on in French.... etc exposer is the key, it is easier and faster when you can find a native speaker to chat with or someone on or further on the path you are on. Hope this helps if you want some practice I can chat with you on here and there are many who will as well. Bonne Chance :)
do you only use DuoLingo?
Have you checked EasyAcademy courses (including B1/B2/C1 vocabulary according to their description I read for Portuguese) on Memrise:
Have you tried http://www.languagecourse.net vocabulary trainer VT (the Android app looks nicer than the web)?
Check their FAQ how to quick learn new words and reaching your personal max.
It adds several dedicated vocabulary about B1, B2, C1 + several different themes (e.g business, travel, words by topic, 3 exams, etc.)