My guess is that it's not a grease problem, you probably have grease. Under "normal" riding conditions 400 miles shouldn't require regreasing. It's likely an adjustment or broken bearing problem. Often, bikes come with bearings adjusted too tight.
There aren't too many things that cause grinding and noise in the front wheel.
You have eliminated the rim rubbing on the brake pads.
The tire rubbing on the fork is another possibility.
If you've eliminated the obvious then the hub bearings being too tight or needing repair is the next place to look.
Without taking the wheel off you can see if it spins freely. With the wheel off the ground give it a small spin. A well-adjusted wheel will stop spinning slowly and smoothly and then move a little in the opposite direction.
I get being hesitant to pull the front wheel but it needs to be done.
You get better at what you do, this is good practice.
Taking off the front wheel (or a rear wheel) and putting it back on is part of maintaining a bike.
Let the air out of the tire and the wheel should slide right out.