Thanks, no clean type right?
No.
It's the same rosin core solder you mentioned in the OP, just as a 1lb spool size, and different diameters. You get more selection this way (wire diameter, flux type, core size <flux %>), and it's cheaper per ounce when comparing apples to apples.
As a general rule, the smaller the wire diameter, the more expensive it will be. Any silver content will also drive the price up. Regarding rosin, it comes in 3 activity levels. From least aggressive to most, it's Rosin (R), Rosin Mildly Activated (RMA), and Rosin Activated (RA).
For a beginner I would avoid No Clean fluxes. Compared to normal activated rosin flux, there are no advantages when hand soldering
I would agree.
It's also important to note that it's possible to mix some no-clean formulas with rosin, but not all (read the datasheet for compatibility). Stick to rosin flux exclusively (solder wire + any separate flux), and you avoid the problem entirely.
It's also easier to find smaller containers of rosin flux than no-clean IME as well.
MG Chemicals Rosin 835 would be an example of a hobbyist friendly sized example of liquid RA flux (they also offer a 1L size). Most of the other brands, only offer a 1gal/4L size as their smallest. I linked this, as it's less expensive to fill your own pens/bottles/brushes vs. disposable pens IME.