Hi
first of all don't panic, that's the worst thing to do, so keep calm while revising.
I did GCSE history and did well, i did Germany 1919-1945 as a topic, but i will try to help give you tips in general so you can apply them to all your topics.
Make timelines! Trust me they are so helpful when it comes to linking dates to facts! Pin the timeline around your room, where you can see it everyday, and just memorise it. That's the simplest way to do well, is memorise!
Flashcards can be very helpful as well, if you can get friends to test you, both of you can learn at the same time this way. They are also i great last minute revision tool to run through before the exam
Mind maps are also incredibly helpful, it can help you learn exam techniques and you can use it to summarise topics once you have revised them a bit.
the basic of history is memorising the facts and dates to use in your answers. And repeating them over to yourself, quizzing yourself or just putting reminders of them around you is the best way to learn what you need
Good luck!! Don't panic you will do great i'm sure