Converting a website from iWeb (AppleMac) to WordPress

I have a website which I created in iWeb software. I have found it extremely easy to manage and change. Apple will not longer support the software in a few months' time and iWeb will already not work on the latest system software. I have been taking an online course on WordPress and understand the basics of inserting pages and posts, etc. My problem is that I have spent weeks looking for a theme which will retain the current look and feel of my existing website and allow for all the photographs which I use on the site and which my customers like. I am looking for someone who can advise on the theme. I am quite prepared to pay for a premium theme but I obviously have to be sure that it will do what I want it to do and I cannot find out how to check this. It is important that I can manage the site myself as I need to make fairly frequent changes. To start I need advice regarding suitable themes. Then I will need to have the site converted and help in managing layout problems until I become more familiar with the software. I now have only about a month in order to get my 50-odd page site transferred to WordPress