French AQA GCSEWatch
use french revision app's (Memrise, Duolingo, Babbel) and go on them for at least 10-15 mins a day speak the language (meaning say the words ans phrases you have learned aloud over and over again and learn the basic phrases) anyone you know who speak in french? if so use that to use to your advantage and practice with them also what are you struggling on in particular i'll probably be able to help (i speak fluent French). Do some practice exam questions, watch you favourite film in french with British subtitles or vice versa, make flash cards or but them ready-made etc hope this helps
When you're learning vocab, make sure you aren't trying to memorise too much at once. Try and learn a few each day and review them regularly so that you don't forget them.
Make sure that you're confident on all the grammar topics that you're expected to know. If you look at page 13 here you should be able to see them all. Lingolia is a great website for grammar and I'd also recommend FrenchPod101 and Learn French with Vincent on Youtube.
Practice makes perfect so make sure you make use of all the past papers available to you. You can find them here. Using past papers is a great way to learn exam technique and pick up new vocabulary. Also, don't hesitate to practice with French papers from other exam boards. Some of the topics may be different but it's still a good way to learn new vocabulary.