The cheapest one.

You don’t need much. You could easily get by with the cheapest one. Remember, it’s pretty easy to upgrade if you need more down the line.

However, Ubuntu does recommend a minimum 2GB RAM for optimal performance if you’re using the 64-bit version of the OS. If you follow that recommendation, you’d need at least the $20/month plan.

Hello, all

Choosing the right Droplet plan depends on your workload. An oversized Droplet would underuse its resources and cost more, but an undersized Droplet running at full CPU or memory would suffer from degraded performance or errors.

You can also resize a Droplet to a larger plan after creation, including resizing to a larger Droplet plan of a different kind. For example, you can resize from a Basic Droplet plan to a larger CPU-Optimized Droplet plan. See the Droplet pricing page for a full list of plans and prices.

You can always check our tutorial on Choosing the Right Droplet Plan

https://docs.digitalocean.com/products/droplets/resources/choose-plan/

Hope that this helps!
Regards,
Alex