Firstly, welcome to Coffee Snobs.
Secondly, how old are the coffee beans?
Older beans need a finer grind; stale beans are the biggest trap for new users.
Although the 0450 is the minimum accepted standard around here for a grinder, it does have fairly large steps between notches and I only ever recommend adjusting 1 notch at a time until you get to know your equipment.
If your beans dont have a "Roasted on" date on the packet find some fresh ones from a local roaster that can tell you the roast date.
Try get some under a week old so youve got more time to play with them.
Any idea at this stage how many kgs of beans youll be going through in a week? If not, how many cups of coffee and do you like them strong or not?
While I remember, are Sunbeam still offering the free course? If yes, do it.