Hi @Dawn109 there are many sitters on here who as @sledgejoyce mentioned, like to book far in advance but there are also others who prefer to apply much nearer to the sit dates. Everyone has different preferences when it comes to choosing and applying for sits.
I would highly recommend adding your TrustedHousesitters profile on to your Forum profile by following the attached link and this will then enable others on here to offer you helpful advice and feedback and will also give your listing extra exposure.