I am a Bio HL student currently and I can help!
Firstly, is biology the only science you are considering for your options? How about the rest of the sciences like Chemistry? Secondly, are you set on doing a science at HL? Or are you okay with doing it at SL and are just looking for advice on which science to take? Lastly, do you know what you want to study in uni? Will it require bio? If it doesn't, then I suggest you take SL.
I'm not a very sciencey person (like I don't love science, I just tolerate it) and personally, I find Biology HL okay. I don't love it till death and tbh it seems a little obscure from what I'm going to study at uni (I'm going to study Law lol). I did biology because I wanted to keep my doors open in the future, incase I decide to take a path concerning Medicine (This was back in Year 11 when I was undecided on what to do in the future. I wasn't sure if I wanted to study Vet Sciences or Law).
If you're okay with memorising content, I think Biology would be a good fit for you. In biology classes, you are bound to have to dissect something at some point (for me, I remember only doing 2 (maybe 3) dissections, but one of them was a flower so idk if that counts). If you decide to take biology as a subject at all, you will HAVE to learn about the human body (e.g. digestion systems, heart, immunity, hormones etc). It won't be as content-heavy as compared to HL if you decide to take SL.
Also if you decide to take HL, there are 5 more topics you have to learn (plants, DNA/genetics, metabolism, and human physiology). Bio is actually one of my slightly better subjects (I also take Chem HL and I'm struggling in that way more). In terms of difficulty, I'd say Biology is the easiest out of Chemistry and Physics. It's really just memorising and with practice, the processes and content will come to you naturally. I don't stare at my book for hours trying to cram processes or cycles in my head as I already know them from continuous practice. It's just the finer details that I try to remember as it may get you extra marks.
I didn't have a very good teacher for bio, but bio is quite an easy subject to pick up. Just give a little more time to it and literally just memorise. Its application concepts will come to you naturally (tbh most of the time its common sense).
The link is a site for both Biology HL and SL topics, which is quite popular with bio students for revision:
If you decide to take HL, you need to learn all topics 1-11, but only 1-6 if you take SL.
I hope my answer has given some sort of insight and all the best!