I would like to access my old iCloud account with my old email in my old phone number how can I do this

A different Apple ID with its password is signed in iPhone see the article What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support ( in fact you are not selling the iPhone but follow the steps ) sign out Apple ID Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac - Apple Support

Then erase the iPhone How to factory reset your iPhone, iPad, or iPod touch - Apple Support

Take out the sim used in the iPhone .

You have to insert the old sim that was used in with old phone number Set up cellular service on iPhone - Apple Support

And set up iPhone Turn on and set up iPhone - Apple Support ( the old Apple ID with its password associated with old phone number has to be signed in the device ) .

New phone, I have 2 email accounts that was linked together, all I had to do was go from one email to the next, now I can’t find my other email to link them on the same page.