Disclaimer: We are classical homeschoolers.
That said, here is what ds#2 just finished for first grade:
9:30 - 10:45: Block 1:
*Phonics (Phonics Pathways)
*Song School Latin (either a page from the workbook or chanting vocab or playing memory with the vocab)
*Math (Miquon math or Singapore math, plus either addition/subtraction drill or word problems)
*Spelling (All About Spelling - can't recommend it highly enough)
11:00 - 12:00: Block 2:
*Writing (Writing with Ease level 1)
*Grammar (First Language Lessons 1 and/or Michael Clay Thompson Island level - he did this with his older brother, mostly along for the ride)
*Penmanship (Handwriting without Tears)
1:00 - 2:00: Block 3:
*History (Story of the World) or Geography or Science or Art ... depending on the day
*Reading (practice with trade books and/or Hooked on Phonics readers)
*Read aloud (separate from the read alouds I do for the above subjects)
All times are approximate, but that is what is scheduled. To me, homeschooling is perfect for "working ahead" - there is no need to stay within a subjective "time frame" of public schooling. Ds#2 was barely 1st grade age (and would have been enrolled in K if we did public school), but he worked just fine with first grade materials, and he often had the benefit of picking up pieces of information from his older brother's lessons. In terms of how long should you spend on a subject each day, it kind of depends on you and your child. We usually did one "lesson" per subject - so with math, that was typically a couple pages of material, for spelling, that was working with ten words and having 2 dictation sentences. For writing and grammar, the programs we use are already broken into easy-to-follow days/schedules. Sometimes we would accelerate a subject a bit or skip it altogether if I noticed attention issues.
Another idea is to "loop" your schoolwork - have a set time for school (at first grade and with no others that you are schooling at the same time, two hours is probably more than enough). Then, write out what you want to accomplish each day into a list form (but maybe plan four days for a five day week). Work through the list for two hours, spending whatever time you need for each subject. Then, after two hours, if there is anything on that day's list that didn't get finished, start with those subjects the following day before starting day #2's list. On good days/weeks, you'll have the fifth day free. Some weeks, you might have a lesson or two to finish Friday mornings. In the long run, it'll just depend on how structured you want to be (30 minutes math, 15 minutes read aloud ... or 2 1/2 hours max of school time and finishing as much as you can and carrying the rest over to the next day). We are switching to a slightly modified loop schedule this next year as my youngest is now wanting to do PreK stuff, I'm expecting in December, and I want to make sure we're hitting that which dh and I feel is most important (Latin, reading and math), and making sure the rest does get done at some point each week.