Retirement tax questions

Thank you so much @macuser_22 , @dmertz 

I have 1 more question:

 

In Jan 2021 I contribute 6k to Roth IRA and immediately recognize my income in 2021 may exceed the limit so after that 1 week, I withdrawn 6k back to checking account already.

 

("may": mean I don't know what my income will be, so for safety I removed it, so no earning is generated)

 

Can I now contribute 6k to Traditional IRA and convert it to Roth IRA (as back door)?

(This IRA traditional account can contain the money I recharacterize from Roth 2020 right? I read somewhere they recommend empty traditional IRA in order to make back door Roth)

 

If so, what forms and how can I input to turbo tax for 2 actions above (for file tax return in 2021)? Thank you so much. 

Have a good day.