"I realise to be happy / Maybe I need a little company"
Well of course... don't we all know that? This song is very unrelatable to me... in a way
The song is transformational. From the first verse she basically describes how she used to feel as an unhappy person and then a moment happened when she realized that she can be happy. The song as a whole basically describes her before and after. The line you quoted is just saying how she realizes how having someone else in her life is something she actually wants now.