You're actually asking two questions here.
1. Create the task
Make sure the following columns are displayed: Duration, Work, Resource Names, Type.
If you have a resource assigned, delete the resource.
In the Work column enter: 2 hours
In the Duration column enter: 3 days
In the Resource column enter: the resource name.
In the Type column select: Fixed Work <<-- this is important.
2. Enter actual work
Here's where life gets interesting. You see, there are several possibilities for entering actual work. You can actually enter it in on a day-by-day basis but if the task isn't complete within the original Duration, what do you want to do? Do you want Project to recalculate the duration or do you want to establish a new duration yourself?
Or, perhaps, the resource actual hours match the originally estimated work hours but, in fact, it will take more work hours and more duration to finish the task.
Or you can enter the actual hours worked in the Actual Work column. But, again, what happens when you enter an Actual Work amount that matches the originally estimated Work but the deliverable still isn't finished?
Frankly, it seems to me that you are still in the early stages of learning about MSProject so it would be best for you to concentrate on actually getting the deliverables produced than it would be to focus on actual hours (compared to the estimated hours). If I were you I would use the column %Work Complete (*NOT* %Complete) and track progress that way.
So ...
create each task with 10 hours of Work no matter how much work is really involved. (So, ignore your 2 hours of work mentioned above)
set the Duration to the expected elapsed time. (So set it to 3 days for this task.)
assign the Resource.
Then, as often as you feel necessary, get back to the Resource and get the %Work Complete (how far along are you?) and get the revised Finish date.
In fact, it's still more complicated than that because entering a specific Start or a specific Finish date creates an automatic constraint on the task. But we'll save that for the future.