First make sure you have covered your bases and Read through relevant sections of The mighty Fine Manuals provided for Metabase. There is both a Operations Guide and even a Troubleshooting Guide
Also a lot of questions asked around here tend to not really be Metabase specific but are more about generic questions how to connect to various databases, setup HTTPS with handling certificates etc etc. For a lot of these questions you want to ask, really - the slightly cheeky answer would be google, Stack Overflow or https://serverfault.com/ is your friend ...
After that here are a few pinters to get ypu started:
more to come here - as this is a wiki feel free to add pointers to insightful posts
... sorry nothing here yet ... I (@jornh) just ran out of steam after wrinting those rants .... also please don't feel shy to jump in and soften the tone, fix my spelling
mistaeksetc etc.
A meek beginning below - let's see where the wind will take us 
Database connections - driver specific pain points, troubleshooting, tips&tricks ...
RTFM: Connecting to databases and data warehouses with Metabase has really good Troubleshooting Guide hints!
| Datebase | Current best summary topic |
|---|---|
| Microsoft SQL Server | Connect Metabase from Linux to Sqlserver Running in Windows (0.27 or 0.28 versions) |
| MongoDB | Metabase + MongoDB Connector for BI |
| MySQL | |
| ... | ... please add more for your favorite DB ... |
Securing connections
- SSL to the Metabase (Postgres or MySQL) application database: How to enable SSL for application DB?
- To databases: MySQL: How to Connect via SSL/PEM files to MySQL? - Google Cloud ....
https://access to Metabase: Operations Guide: Customizing the Metabase Jetty webserver Different environments: Cloudflare, but has generic info as well, Using https: with Docker includes using Nginx or https-portal- A fully automated HTTPS server powered by Nginx, Let's Encrypt and Docker.
General automation
- Automated startup: Linux: Newb - run jar in background
There is now a chapter in the docs, you can adapt to multilog if you want but works well as is: Redirecting… - Windows: Run Metabase as a windows service! - Multiple Metabase on the same server
- Migrating data: Metabase Migrate
- Backup: .... or ...
- Operations Guide: Backing up Metabase Application Data ... oh and remember to test you can actually restore from your backups. Backups are worthless - it's the ability to restore data to a new machine that has value 
Oh, and if you are still with us ... then, yes of course ... after having looked these places and if you still haven't found the answer to your question, or is very new at all this and don't understand all the tech babble - welcome!, glad to see you ... and ask for help or get a quick pointer in here. In the end we all want this to be a nice community for everyone wanting to use Metabase ...