If you're using a CMS or another php script the first thing you may want to do is to enable cache. Cache reduces the server load and increase loading speed.
You can also improve the speed of your website using an optimisation tool. We recommend Page Speed, available for chrome e firefox.
Before opening a ticket check the site speed using pingdom and analyse it with https://gtmetrix.com to measure the actual speed of your website and what can be optimised.
You might want to enable a CDN like cloudflare, we have a tutorial about this.