And I would interpret your question as saying "How can I brand my site to look like my own?" I am covering a number of possibilities here too. You haven't said what you current position actually is, so I am assuming that you are planning this to be opening soon.
Use a theme you can easily modify. Well, most themes are easily modified now, you can change colours, change banners, change the appearance by changing the settings of the theme. Depending on how far you want to go, you might want to start with one of the basic themes, and modify that to something approximating what you want. Documentation for doing that starts here. Later, as you become more confident with what you are doing, you may want to switch your theme to something more sophisticated, like the Fordson Theme, there are lots of them.
There is a couple of other things you may want to think about first though. As Mary suggested, use the MoodleCloud to become familiar with using Moodle, that is an excellent place to start. Understand though, MoodleCloud is, of necessity, somewhat limited and it may very well be that you will outgrow it fairly quickly.
I would suggest you use your desktop or laptop to set up a Moodle for yourself. This is your test site, no-one else has access. You will need Apache, MySQL or MariaDB or PostGreSQL, and PHP, (preferred v7). Also, include phpMyAdmin or phpPGAdmin to manage your database externally. Obviously we don't know what your tech skills are, but if you have good skills you should be able to do this all yourself, or likely you will know some whiz-kid who could help you set it all up. Or you could download and install the XAMPP Moodle, but don't expect it will last too long, it is inflexible and when it starts to go wrong, it is better to delete the whole lot and start again. Test everything here before you introduce any change on your production site, it will save you a lot of heartache if it goes wrong.
You may, eventually, need to have your own domain with your own Moodle, in which case, you may require a good service provider. There are lots of them, all over the world, just realise you may be facing some unknown issues with regard to usage if you are using someone like GoDaddy or similar. You may want to use a Moodle Partner, they will help you a great deal. This is your production site and should never be used to test stuff, that is what your private Moodle is for.
Moodle is useful in a whole range of areas, and I would suggest you go to this post and read it carefully. There is a lot of really good ideas here about Moodle, what can be done, what is achievable. It is aimed at a school district setting, but the attitudes behind the post are what you may want to look at in some depth. Welcome to the rabbit hole, Elsie, enjoy the ride..