Hi Christine. Just thought I would add that just because there is a field doesn't mean that you have to fill it in. Most genealogy databases will work just fine if you put the name and surname and approximate year of birth. If you haven't got copies of the marriage documents use 25 years before the year of marriage as a starting point. Kevan is a pretty uncommon version of the spelling (Kevin is a lot more common) of the name, and the Walmsley surname is also not particularly common. See what records you get. Don't forget South Africa as a possible destination. They may, as the family members of Charles Dance in a recent Who Do You Think You Are episode, have travelled on a ship bound for Australia but disembarked in Cape Town. Lots of UK people settled in South Africa. I don't know that much about South African records. Ancestry Library Edition is also worth a try because people post their own family trees as well as all the more 'official' records.
It would be a good idea to post what you know already on Wikitree as by going back to earlier generations you may encounter profiles for your ancestors that have already been submitted by other Wikitree members.
Please do only submit the names of people for whom you know who the parents are, because if you are missing these, Wikitree automatically creates Unknown profiles which are not then run through the database of already existing profiles if you come back later and add the actual names. So don't add a father or mother unless you have their own names and some dates (birth or death) so that a search can be run for existing profiles and don't add siblings unless you have already made profiles for both parents.
I am happy to help you get started. If you create a profile for yourself and profiles for your own parents then we can extend further back from the available records. We ideally need people who were born between 1900-1920 to get started. If you have people in your tree born after the Sep Qtr in 1911 the birth index includes the mother's maiden name. If the person has not died then you make their profile private (yellow icon) so their exact dates are not displayed. See my profile Hunter-8415 by clicking on my name to see an example of a profile with certain features restricted. My profile setting is private with public biography displayed. I have this so people can see the links I have to my favourite web-based sources.
Regards, Andrew