Why I have started an account on/using italki.

This is my first time writing on italki. I´d like to learn english and improve my writing skills.

(The verb 'would like' makes the verb afterwards have a 'to' in front of it. 'I'd like to learn, I'd like to improve'. A normal 'I like learning' is okay. 'Improve' doesn't need a 'to' because the 'I'd like' is affecting 'improve' as well.)

I met a guy from London who talked/spoke (spoke sounds better) to me about this social media site. I always have problems passing writings exams.

(Writing doesn't need an s, because it is a participle, that describes nouns. Eg, running boys, talking mothers, slamming doors.) 

I need to practise more and more, to get enough levels

(grammar is okay for 'to get enough levels' but it doesn't make sense. 'To become/get good enough, to have a high enough level' is better)

to feel ('confidence' is the effect of getting good at English. 'So I can feel' is better than 'to feel' here) confidence with myself.

It would be a pleasure, if you could correct my mistakes in this simple text.

Thank you in advance

Oscar.

(Well done and Good luck. This is my first correction too, so I hope it isn't too confusing!)