Error message when activating plugin

Hi,

Great plugin. I have some questions in which I would appreciate to get some answers in.

1. The following message appeared when I installed the plugin:

The supplement generated 297 characters of unexpected output ( unexpected output) during activation . If you notice an error message such as ” headers Already late,” problems with the flows or other errors , try to disable or delete this supplement.

2. It says that I only have a 30-day trial. But what happens when it ends with the plugin?

3. How can I remove ALL decimals in the price? Right now some are removed and some are not. Those who are not removed are written 120.00. I don’t want the “.00”

Thankful for response.

https://www.ads-software.com/plugins/instantsearch-for-woocommerce/