Wordpress is an eldorado for a web desinger. There is SO much you can do in Wordpress, and the reason for that is that there are thousands of add-ons/plugins. If you need a booking module, you can select and scrape in plugins that you can install and use.
It may sound pretty great with many plugins to choose from, but sometimes it can lead to conflicts, as not all plugins are compatible with each other. It can cause your website to be strange, or it simply crashes. To find out which plugin caused the misery, one usually has to disable one and a plugin until you find out which of them created the problem.
Fortunately, it is possible to disable and activate a plugin without losing any data, so it is completely safe to do. It also makes it quite easy to test out a plugin to see if it works with the others and that it has the features you're looking for. If it doesn't fit, you can delete it again without any damage.
Be a little picky
You have a need and need a plugin that takes care of it. When searching, it comes up page on page with current and not so relevant plugins. But, how do you know which one to choose?
A good starting point is to check when it was last updated. If you stand between two where one is updated 6 months ago and one that was updated 2 weeks ago, you should choose the last one. It's a good sign that the plugin is still looked after by those who have made it.
The next thing is to see if it is tested out with your version of Wordpress. Occasionally it may work fine in spite of it, but it is absolut to anbfale to try one that is tested.
Also always read what's written about the plugin before installing it. Check if the free version gives you what you need or if you have to go for a paid pro version. If you have to pay to get the feature you need, then check out some other plugins too before paying for the pro version. Sometimes someone gives for free what others charge for.
Also look at what others write about it and how many stars they give it. If everything looks good, you can install it.
Then check that the website is working properly.
When things are slow
Using many plugins can make your website slow, since there is a lot of data to be retrieved from the server before the page can finish loading. The solution to the problem may be to not use as many plugins. Or to download another plugin, which, addresses the problem by loading data into a cache - a cache in your browser/browser. So instead of retrieving all the data again, it uses what's in the cache, which goes much faster. It also minimizes Javascript and CSS files so that they merge instead of loading separately. Uploading a file is faster than uploading more.
You can clear the cache if you need it. Either by going to settings in the browser you use and deleting there, but you can also do so by using CTRL+SHIFT+DELETE. Please note that if you were logged in somewhere, you'll need to log in again.