It's not necesary. For a very very basic processor you have to do all combinational circuits for the operation you want, add, compare , multiply ( why not ) , etc. All operation takes the data (binary word) from 2 register (for example) and this has a number of bit. The register are flip flop (types D).
There is a register (PointerCounter-PC) which has the value of the memory location that procesor will read (put in same register), very times it's read this register increase (a lot of procesor allow chages the register's value whit same instruction). The register(PC) bits are put on the address bus.
The operation has to be like this. The first data is an opcode, which has the type of operation you want to do and the registers you are going to use (to allows them for the two next movements), an put it on a register (responsible for the instructions for later to decode it ) the other two data has to be the values, operators. When the procesor has every thing in the register, it decode the instruction, whit a decode ofcourse and it allow the corresponding combinational circuit will operate with 2 register where the data was stored and then save it to another , or in memory.
As register are flip flop there must be a synchronism, between the data move.
That's the basic, you do not have to learn about VHL but if you want to do a big thing, yes.