Hey hey! I'm in the same boat as you, I'm the only one in my class who hasn't lived in France and isn't French ahah.
Tips would be to write out general answers for things that will almost definitely be asked (school, subjects, plans after school, family, hobbies etc.) write them out and have your teacher check them, but in addition to making sure that they are correct, try and weave in as many grammatical structures as you can. Then practice reading them aloud or reciting them as you walk somewhere, don't make them too pre-prepared though as it seems unnatural, be ready to adapt the answers, just know in general what you will say
For example instead of just saying something like "Le week-end dernier, je travaillais" add more detail, something like "et j'étais très fatigué car je n'avais pas très bien dormi"
So by adding more detail you can showcase your knowledge of grammatical structures especially the more advanced ones like future perfect, conditional perfect and plus-que-parfait.
Also try to put in subjonctif stay aren't as obvious such as "pour que je puisse" (so that I can) or "bien que nous soyons..." (Although we are...). Just a few examples.
Also ask your teacher if you can go in at lunch or something to practice.
To improve listening/accent/flow try watching one of your favourite shows in French- also observe the use of filler words such as "bref" "euhh" or "alors" just to make your speech sound more natural.
Good luck!