There are so many WordPress themes out there, some free and some paid. Some offer tons of customization and some offer very little. But which theme is right for your business website? There is no one size fits all for this answer.
The first question you have to ask yourself is, what is the general theme for the site? Is it a portfolio site? It is a corporate site? It is a consulting site? The answer isn’t a “business site”, what specifically type of business. This is to help narrow down the themes for you.
How much customization do you want? All themes offer some customization but some themes offer more customization than others. Unfortunately sometimes you can only find this out by trying the theme, or by asking someone you know (if they have used that theme, or what theme they use).
Do you want to drag-and-drop things onto your pages? If so then you want a page builder (see this WPBeginner article for a bunch of the most well known page builders). If you do use a page builder make sure your theme works well with it, otherwise you will try to change something and not be able to change it.
Did you want support? If you are making this site yourself then you should consider getting support from the theme creators, and how quickly do you want support to respond? This determines how much you will pay for the theme / support. Some themes don’t offer any support, some themes only offer support via a forum (and the theme creators don’t say how long on average it will take them to respond), and some themes offer support via email to ensure personal support and you get your answer quickly.
Now that you have narrowed down your theme choices, go to the theme directory on WordPress.org and take a look through the themes there, make sure to pay special attention to customization, drop and drop support, and support. Something to remember, you may look at the picture of the theme and think it’s a good theme then go to the preview and it look horrible. That’s because theme developers don’t want to create a complete customized site just for one theme. Make sure to go to the theme homepage to see more details, and if they offer support (or if there is a paid version of the theme).
If you have spent more than 5 hours looking through various themes on WordPress.org and can’t find that you like then go over to themeforest (referral link). For example, if you are looking for a restaurant theme then check out Dina (referral link), if you are a magazine company then look at Paperback (referral link) . All the themes on themeforest cost money, but it helps to support the developers (as well as you get limited support). Themeforest does offer some themes for free, for the month of July (2018) the Vinero theme (normally $39 USD) is free.
It may take you a long time to find the right theme, if through all the looking you just can’t find a theme but you want to use a page builder, go to the page builder site and see what themes they suggest (and are usually 100% compatible with their page builder).
Once you have found the WordPress theme that you think is going to work, you’ve bought it (or got it for free) then upload it to your site, but don’t activate it just yet. You can preview how it’s going to look by clicking on the preview button. It may not look exactly like how you want, but if the general preview looks good then go already and activate it then you can tweak it to fit.