refinance or sell-looking to purchase another property afterwards

[Nick Shapiro]

hello! i am a 25 yr old carpenter, when my father died i assumed his mortgage. i have since renovated the entire house with plans to sell it. the mortgage is about 250,000. i borrowed 20,000 from a friend to cover materials for the renovation, and there is also a 20,000 lien on the house. after my renovations the value of the house is 450,000. i know nothing about investing or real estate, but started listening to the bigger pockets podcast to begin my education. My plan was to sell the house, pay off the mortgage,lien, and construction materials loan. I was then going to take my profit and invest in another property-either a single family or duplex- renovate it then rent it out. my father refinanced his loan so the mortgage has already been refinanced once, it went from a 30 year mortgage to a 40 year mortgage. after listening to the bigger pockets podcast it brought up a few questions for me. Would it be better to refinance again and keep this property as a rental? is it best to stay on the path of cashing out and finding another property to start my real estate career? is it even possible to refinance again? how exactly does refinancing work? when you refinance what happens to your loan and monthly payments? what happens to the equity you have? I'm completely new to real estate, as I'm sure you can tell by reading my questions, i was going to searching through google for my answers but i figured id have an easier time understanding if i could talk to the experts on this forum. I plan to obtain several properties within the next 10 years to rehab and rent. what would you do in my position? what would give me the best start?