just beginning

Its a shame you are being taught AHDL. Its is essentially a dead language now and it has very little support. Quartus will still compile it but it is very limited in scope compared to VHDL or Verilog. It will be useful from a Hardware basics POV, but for actual design VHDL is far superior.

All HDL languages are not programming languages, they are Hardware Description Languages. The best way to learn them is first to understand the basic hardware components. When designing a system first you need to work out whats going on before writing any code. HDL is really just another way of writing a circuit schematic. If you come from this angle hopefully it will help you by not overloading your learning.

I think KM above has expalined your main questions above. Ill try and expand on them, using VHDL, assuming you understand some basic logic;

If we have a signal a, in VHDL a literal would be:

A <= '1'; or A <= '0';

This means 'A' is always 1 or 0;

an equation using primitive could be:

A <= B and C;

A is now the boolean AND of signals B and C;

you can write much more complex equations with primitives:

A <= (B and C) xor (D or E);

As for standard logic functions, It may mean registers. The basic template for a D type flip flop in VHDL is:

process(clk)
begin
  if rising_edge(clk) then
    q <= d;
  end if;
end process;

You can make this more complicated by putting boolean equations in place of D above, so the output of a primitive logic equation has a D type flip flop on the end of it.