I'm just going to jump in with a really good piece of advice I was given early on - don't say you're inexperienced, don't say you're just starting out, don't say you're trying to get your foot in the door. Just tell your clients why you can do a really good job for them (plenty of knowledge about the subject, writing qualification etc.) and get that bid in. If they ask for examples (which they almost certainly will), then it's up to you at that point how honest you are, or whether you want to tell a white lie that all your experience so far has been with a content mill (e.g. Copify and the like) and you can't point them directly to examples, or whether your previous writing has been done in house at a job (and ditto, because intellectual property, etc.).
Yes, you'll speed up as you do more and get more clients, but otherwise your writing style is pretty much your writing style. Have a look at a few company blogs for the kind of company you'd like to write for, and make a note of voice, style, content, length etc.
You might also want to think if there's anything you're not comfortable writing - either subject matter, or type of communication. I won't touch press releases, for example (they make me want to punch myself in the face and take me about an hour a word), nor anything that I'm not ethically on board with.
Good luck, all. There seems to be quite a lot out there at the moment, and with the vast majority of businesses still working remotely, I don't think there's ever been a better time to start.