[Brutha]

First I'm myself, not very good at starting conversations but I think I have still some worthwhile ideas to share:

I don't have any topics in my head, and I can't talk about myself either as [bI'm quite literally a no-one[/b]. I know that it'd be better to be more interested in the other person,

Maybe you should also be more interested in yourself?
If you don't find yourself interesting why should someone else?
If you can't even find yourself interesting how can you find other people interesting?

I know that it'd be better to be more interested in the other person, but I have this feeling that my conversation partner would also like to know about me, otherwise s/he could be talking to a wall as well.

According to Sartre there is something called Being for other, you need other people to exist as a person.
People exist in the mind of others.
You can only really feel successful or intelligent by being judged that way by other people.
You can think that you are intelligent and the world doesn't understand your intelligence, but it isn't the same feeling as knowing that others see you that way.
Humans evolved to strive under social idea exchange.
I once read (I don't know whether it's accurate) that people who win Nobel Prizes live on average five years longer than their peer who don't.
Judgement by other people means something to people and is needed to be mentally healthy.
It's of great value to people to judge them as the person they aspire to be.

That lack is probably also the reason why you judge yourself as uninteresting, because you lack that feedback of what other find interesting in yourself.