You are correct. You will be subject to Self employment tax. You are considered a Dealer from your description of buying and selling without renting properties. With that being said. You will also have additional deductions that can be written off in your small business. Also a credit for 1/2 Self employment tax and a Qualified Business income deduction.
Here is a guide to small business deductions:
https://turbotax.intuit.com/tax-tips/small-business-taxes/taking-business-tax-deductions/L5RueYPVS
Here are 2 links to help understand tax implications:
https://blog.turbotax.intuit.com/self-employed/5-tax-implications-and-tips-if-you-flip-things-for-pr...
https://www.propstream.com/real-estate-investor-blog/flipping-houses-and-taxes-what-you-need-to-know
Yes, You can put money into a retirement account to lower taxable income. This does have limits.
https://turbotax.intuit.com/tax-tips/retirement/boost-your-retirement-savings/L3lryQHVz
Please remember these limits apply to all retirement accounts. Employer and Self Created.
Yes, TurboTax has the ability to help you prepare these returns. Since this is a new venture and you do not have experience, I would recommend having it prepared for you.
