Hi,
The C64 is more of a home computer than a personal computer, but it is really a good machine to learn basic assembly concepts on, I'm in Hungary, so if you are in Serbia then you are almost my neighbour 😁, in Hungary the C64 is still relatively cheap on our local "ebay equivalent" sites, so Serbia might also have some available to buy in some online shop. Note that the C64's disk drive is sometimes rarer than the C64 itself in Central and East Europe, but if you wish to program on the actual C64 and not develop on a PC then transfer the program to the C64 then a disk drive is a lot better than the cassette based storage.
Do note that you will have to source an assembler separately as the C64 in-built language is BASIC. (in fact it is more of the OS of that computer than simply a programming language)
However the C64 is fun to learn on, the MOS6510(Which is basically a slightly modified MOS6502) has a quite straightforward assembly language(The zero page is a bit weird coming from modern architectures, but very useful), the HW sprites of the VIC-II and the sound capabilities of the SID is relatively easy to program and impressive for the era the computer were made in.
"A process cannot be understood by stopping it. Understanding must move with the flow of the process, must join it and flow with it." - Dune