ANSWER - It very much depends what you mean by the term ‘familiar’ as the word is commonly used for different purposes these days. Historically a familiar would be an animal that a witch would occupy (possess if you like) which would allow the witch to leave her body and use that of the animal for journeying.
Influences from Shamanism have led to the term being used as a synonym for spirit animal. This is an animal which can be summoned to the individual in a vision or trance and who may have wisdom to impart to the caller.
A more generic interpretation of a spirit animal is an animal which has characteristics a witch strongly identifies with. Searching for this animal can be a positive meditation exercise as it encourages us to be introspective and to understand our own personality traits as we relate them to different animals.
The term familiar is sometimes used in a modern and colloquial sense to refer to the pet of a witch. This doesn’t have much historical precedence but seems to be widely used, particularly among the younger community. (Which is a good thing, language and definitions should change and evolve with each generation, it helps keep our craft relevant.) I’d argue that a pet who is going to be referred to as a familiar should have a close spiritual bond. Not every animal owned by a witch is going to qualify. I have four cats, all of whom I am very fond of but none of whom I have bonded with to the extent that I would consider them a familiar. Beware of trying to push your own hopes onto a pet. Even the most beloved animals in the home may never have this kind of relationship with you.
In terms of attracting a familiar I think it is very much about which definition you mean. Think about what the term means to you. If you believe it to be a physical tangible creature then start looking at the type of animal you may be comfortable having in your home. If you are looking for a more ethereal relationship then start to put some time aside for meditation and open yourself up to the possibility of being called by the animal who chooses you.