SealSong talks a lot of sense. I am an adoptive mum of a child who does have significant attachment difficulties. He got that way because he was seriously neglected in his earliest months. You have to try hard to create a diagnosable attachment disorder. Nobody has yet found a reliable measure of attachment and used it in a whole population, so we really don't know how 'attached' most children are, or whether it matters to their future lives exactly how well attached they are within the 'normal' range.
In general, most parents and most babies are hard wired to respond to each other in particular ways - playing, chatting, singing, mirroring what the child does - and this promotes a secure attachment. It's why people talk about 'good enough' parenting.
If you are generally happy to be with your toddler and they with you, and you feel able to meet most of their needs most of the time (which includes a need for loving sensible limits!), I think you'll be absolutely fine.
And as others have said, strong relationships with others are a good thing. You are the child's first, most enduring idea of what a relationship should be. If that 'working model' is a good, secure one, they will have the confidence to expect the same of other adults, and hopefully will be rewarded.
To give you an eg of that, I have two adopted children. The one with much 'better' attachment is clear we are their no 1 secure base, but is a friend to the whole world. The one with more problematic attachment finds it very hard to build relationships and friendships outside the family. He hasn't had enough experience of loving trusting relationships to be confident about building them 