improve speed..

It is hard to say for sure what is causing the slowness but I have a feeling it may be to do with your host. Your site is rather slow to load from page to page (~4-5 seconds) and this is the same performance from the search suggestions plugin. I would say that suggests it is either caused by a slow database (over subscribed shared hosting) or network congestion.

You can see in this speed test: https://tools.pingdom.com/fpt/#!/en7ofI/https://bmtutoring.com/ that your site is held up dramatically (yellow bars). This is all down to how long your host is taking to process and retrieve the data.

I would contact Bluehost to see if they have any suggestions.