Renovation, no one here could guess that one without knowing lots more. 30-60 days should be able to fix most anything.
Now to sell it and that might be the hard part.
Congrats on your new business adventure. It can, or cannot be a great business. I want to start off by letting you know that it is just my opinion that I am giving and I hope you take it constructively.
Many people in the last several years have lost everything, including their shirt trying to do what you are wanting to do. It is a business that requires DEEP pockets to be in so first off, if yours aren't deep...move to the next idea. It also requires a lot of knowledge about the real estate industry, so if you don't have that, you have two choices...get it, or move to the next idea.
In most states, it is not to terribly complicated to obtain a real estate license. If you were to open a different business that required a license, you would get one. I would recommend getting one in this business as well. If you think it's too expensive to get one, refer back to the deep pockets part of this answer.
The last thing I will leave you with is this....
If you budget X amount of money for a project and wish to complete it in X amount of time....
Double all figures involved.
If you budget $50K to renovate, it will be upwards of $100K
If you budget 6 months, it will take a year.
This is not alway the case but why not be prepared.
I'm sorry to say that if someone needs to ask the question you asked, then they are not quite ready to get in the business just yet. It's like a freshman in collage asking how long it takes to get a medical degree or how many ours do attorneys work. You just don't know enough about the business to jump in...YET!
All the best!