Struggling with unexpected downtime during my first cloud hosting migration: best practices for minimizing impact?

hey everyone, really hoping for some guidance here. i'm a solo founder, just launched my first tiny SaaS app a few months back. it's growing slowly, which is awesome, but i'm still on a shared hosting plan and starting to feel the limits. the plan was always to move to a proper cloud provider (thinking AWS or DigitalOcean) for better scalability and reliability.

i finally decided to make the jump last week, thinking it would be a straightforward process. i bought a new cloud server, set up the basic environment, and then tried to migrate my WordPress-based SaaS site and its database. that's where things went a bit sideways, and i've had way more downtime than i anticipated.

here's what i attempted:

• i manually copied all the files over via SFTP. that seemed to work okay.
• for the database, i exported it from the old host and imported it into the new one. i know this causes some downtime, but i figured it would be quick.
• then i updated the DNS records to point to the new IP. this is where the real trouble started.

the problem is, after updating DNS, my site was inaccessible for hours, not just minutes. i kept seeing the old site, then nothing, then the new site, then nothing again. it felt like forever, and i had a few users complain about the site being down. i know DNS propagation takes time, but this felt excessive and very inconsistent, leading to prolonged downtime.

i'm trying to learn as i go, but this whole migration thing feels a lot more complex than i initially thought, especially when trying to keep downtime to an absolute minimum. i'm worried about trying again and causing even more disruption.

so, for my next attempt, i'm wondering:

• what are the absolute best practices for a beginner to minimize downtime during a cloud hosting migration?
• are there any specific tools or strategies for database synchronization that can achieve near-zero downtime, even for a simple MySQL database?
• any pro tips for handling DNS changes to prevent these extended periods of inconsistency and downtime?
• what are common pitfalls for someone like me, who's not super technical with server stuff, that i should absolutely avoid?

anyone faced this before? any guidance would be super helpful!