it's been said before, and I'll say it again.
you obviously don't understand the I2C protocol. you need to learn about it before you even think of trying to implement it in software.
yes, you need to manipulate both the SDA and SCL lines when communicating, and both of them have to be done in specific manners with proper timing. the SCL line is not just a simple continuous clock signal, it is used as both a clock during data transfer, as well as in start/stop conditions, acknowledge, etc.
it will be MUCH easier to simply READ about the protocol than trying to ask people on this forum about every single detail. we are of course willing to help, but if you want us to spoon-feed you every single aspect of I2C communication, when there are plenty of resources out there for you to use if you just take the time to read them, that's a bit much.
here's a document titled "the I2C bus and how to use it (including specifications)"
https://www.electro-tech-online.com/custompdfs/2005/07/i2cHowToUseIt1995.pdf
that will tell you absolutely everything you need to know about the protocol, and then you will have a solid base from which to start writing your program. I just wrote a full set of I2C routines for the PIC microcontroller yesterday for one of my own projects, with ONLY that document for reference, so I KNOW there's enough in there to get you going.