Hi, dear. There are some verbs in English that must have been followed by -ing. Those are, for example, deny, discuss, finish, mention, pratice, quit, resist, suggest, etc.
There are some verbs which can be followed by a verb + -ing or an infinitive verb. Examples: Like, love, stop, etc.
"I like learning\to learn new things such as learnING to play the guitar."
(After as, use the gerund form of the verb, because a verb that follows a preposition must be in the gerund. And everytime you want to talk about musical instruments, always use THE before them.)
You know, I would say your sentence like this:
"I like learning\to learn new things such as playing the guitar."
It sounds better.
I hope I have helped you.