That is the simple past tense with a gerund as the verb's direct object. Learning serves as a noun in your sentence, not a verb. We call that a gerund. I started the movie. (the direct object is a noun) I started watching. (the direct object is a gerund, which functions as a noun) I started studying. (the direct object is a gerund, which functions as a noun)

I think you are referring to the Gerund: Attending meetings is on of my tasks I started working at 6pm. I liked swimming https://www.ef.co.uk/english-resources/english-grammar/gerund/

The verb to walk. If I am currently doing the action I am walking and if the action has already passed then I walked. For example: I’m walking to the store( this is happening currently) I walked to the store (this has already happened)

In English there are a number of different grammatical uses for -ed and for -ing. Which use of -ed and which use of -ing are you referring to?