hiya,
year 12 here
i’d say it’s definitely possible if u put the work in, try stay consistant for the rest of year 9, and 10, and really go for it in year 11
me personally i went from a range of about 6-8 in year 9 to 8s and 9s in actual gcses so improvement was defo there
in terms of specific tips i’d just ensure u revise all ur subjects not just your favourite few, which is always really tempting
good luck !