Zig - most portable modern C alternative, you can consume C/C++ with ease, so if there are C/C++ libraries that'll help you kickstart your idea, you'll just need to include the headers, that's it

Comptime feature is unmatched, it's not something weird as macro, you don't need to learn a new language on top of the language itself, it is zig code

You can crosscompile with EASE to what ever target you want

My 2nd choice would be D

Rust? you'll cry when you'll have to wait 10+ minutes to compile a single line change, and the code becomes quickly unmanageable, the community is sectarian, elitist, and will hate you for criticizing their "god" language

Go? best language for servers, not so good for anything that require low level