Fix a slow wordpress site

I have a directory based website which is running very slow.

I have already paid someone from here a few months ago to speed it up, they added a few plugins and it did seem to help but there is still something not right, it can take up to 10 seconds to load the homepage for the first time!!

I need this sorting once and for all. I don't know if there are some plugins that are conflicting, whether the whole site needs optimising or whether I need to change hosting companies (though I can't believe this would be the problem as bluehost are highly rated in the UK and have said they have done everything their end to have the speed as high as possible). Every single page on my site takes a long time to load for the 1st time.

So whatever is done to fix it needs to be thorough and not just an added plugin or two. I am hoping the fixed amount would be enough for a really good job.

Thanks for taking the time to read and look forward to hearing from you!

The site is

https://loyaltolocals.co.uk

Paul