Change how I portray myself?

Im in secondary school, have been fir 4 years, I entered with the mindset that anyone who tried to be funny that I didn't find funny I should point it out to them and make it obvious I didn't like them, second year in and those people are my best freinds and I've shaken up my attitude towards others.

I've always been one of the people that nobody really acknowledges, and I'm fine with that, my GCSE classes started in September and my freinds are all together and I'm in new classes so I have to make new friends, the thing is that me being irrelivent has stuck and people just don't want to talk to me due to the fact I'm this unknown guy in the school. I have tried, and I have made... accquaintences, but I act like a complete fool, I come off as really naive and act stupid and clueless and talk for ages about the randomest stuff, which ends up driving everyone who actually gave me a chance mad.

Is there a way I can go back on myself? I feel like the only way I can make small talk is by shooting myself in the foot but I want people to actually want to consider talking to me, since its usually me that initiates the conversations due to my reputation (or lack of one).