Advice on first nextcloud set up - Local, Docker container? Something else?

Hello. I am seeking some guidance and advice before setting up Nextcloud. I tried to set up previously via a provider, CloudAmo, however after doing this could not locate a nc url/dashboard area. Not sure if they restrict admin access or there. Anyway, some ideas of set up that I had…

I have an ubuntu laptop and a fastmail account. Per this reddit post it seems I can use my fastmail cloud file storage through nc - great! Given this, do I even need a provider? I.e., would it be feasible to host nc locally, use the UI to set up storage with fastmail and voila? A caveat is that I often shutdown and restart my laptop, so it would not be up 100% of the time. I’m thinking I could just sync my phone to a directory locally manually whenever I want to sync and have a folder on local linked to nc and in turn linked to fastmail. Does this set up sound plausible? Or am I asking for pain?

Another idea I was thinking. I like the idea of portability and recently worked on a few projects using docker. I like the idea of using a container to run nc, where I would in theory be more free to move from one cloud provider to another. But a piece I cannot square in my mind here is the db element. I’d still like to use Fastmail cloud file storage as my ‘main’ storage area. But, if I hosted a docker nc container somewhere in the cloud, is it going to be more painful than otherwise to manage?

Note that my tech aptitude is amateur to intermediate. I prefer less pain and suffering where possible.

Are either of my two ideas credible? Either host nc locally on my laptop and only run on localhost when I need to sync on demand or run a docker container in the cloud somewhere with the idea being that my set up would be more portable than otherwise? (I don;t see how, since all my stuff is planned to be with Fastmail anyway, not on the container, I think I just want the container for the web ui, right?)

Advice, pointers or hand holding most welcome?

This may actually be more accurate

What operating system do you plan to run your installation on?