These are topics you need to study to pass an exam at B1 level, such as Cambridge English Preliminary:
Both, either, neither
Broader range of intensifiers; So, such, too, enough
Comparatives and superlatives
Conditionals, 2nd and 3rd
Connecting words expressing
cause and effect, contrast etc.
Modals - must/can’t deduction
Modals – might, may, will, probably
Modals – should have/might have/etc
Modals: must/have to
You can also see which grammar topics are associated with other CEF levels.