[weedpeg]

I think I am qualified to answer this question. When I started my own company (running for 3 years now), I was already writing code for 5 years but that was not web stuff. I was mostly writing wireless communication protocol(firmware). Then i decided to build a SaaS product. I started with Django and i would recommend that to anyone simply because it comes batteries included. The documentation and whole ecosystem of django/python is great. Also it is used by many large companies in production so you can go a long long way with django itself.

For apps i would recommend Flutter. It's great, one code base for ios/android. Compared to react, i think flutter is easier as you dont have to deal with CSS/HTML etc.

Regarding hosting, start with heroku. It's super easy, does the right things for you out of the box. Security of something you need to do right from day 0 and with doing AWS/GCP yourself, you may be better off getting heroku to take care of this for you instead of doing yourself.