Pick a popular base system. Node.js, python (flask or similar), maybe .NET core. all of them are easy to learn for a C programmer. The real learning curve is

Pick a popular base system. Node.js, python (flask or similar), maybe .NET core. all of them are easy to learn for a C programmer. The real learning curve is the surrounding deployment systems and package managers. npm, pip and nuget etc. IMHO you'll be better off not just learning the language and libraries but do a deployment as well.