Hiya,
I'm a 3rd year undergrad looking at applying now for bio phDs starting next year but I can't be sure what my chances are without research experience.

I had a very brief non lab based placement last year and was hoping to get better experience this summer but obviously COVID happened and so my summer placement was cancelled.
Without experience i have no idea what to write in my personal statement/ cover letters to actually make them worth looking at.

Those doing a phD were you expected to have/ did you have much experience when you applied?

I had no research experience when I applied. I would say a lot of PhD students have no research or minimal experience beforehand. It is nice if you have some but not having any doesn't eliminate you. If you are stuck for what to write about, talk about; your dissertation, any small project, your motivations or what you want to research. I applied to funded engineering PhD with a set project and for my application I talked about the research project and possible experiments.