Try solving some crackme's. They're binary executables of various difficulty (with rated difficulty), where the goal ranges from finding a hardcoded password to making a keygen to patching the executable. They used to be more popular, but I'm guessing you can still find tutorials on how to get started and solve a simple one.

Take this with a grain of salt as I’m not an SME, but there is a need for volunteers on reverse-engineering projects such as the Zelda decompilation projects[1]. This would probably give you some level of exposure, particularly if you have an interest in videogames.

[1] https://zelda64.dev/

I found https://pwn.college to be excellent, even though they mostly focus on exploitation, pretty much everything involves disassembly.

As a very first step, you may start playing with https://godbolt.org/ to see how code is translated into lower-level instructions.

Writing your own simple programs and debugging/disassembling them is a solid option. Windbg and Ida are good tools to start with. Reading a disassembly is a lot easier than coding in assembly, and once you know what things like function calls and switch statements, etc. look like you can get a feel for what the original program was doing.

you can compile your own hello world and look at the executable with x64dbg. press space on any instruction and you can assemble your own instruction in it's place (optionally filling the leftover bytes with NOPs)

first you need to learn assembly, second you can start by downloading ghidra and directly start decompiling some simple things you use and seeing what they do.