New website

I have a 5 page Drupal website with a poorly functioning CMS that needs replacing. I am inundated with Russian spam, it is very difficult to navigate and it doesn't display well on mobile phones or IE. Functionality, ease of use ( adding content etc,) responsive and displaying well across all browsers are important. The current site is www.advtechnical.co.uk and is hosted by Ionos. I like the look but it doesn't attract any visitors. I need a new site not a redesign but I don't mind keeping the current theme. No decisions until 01 April 2021 with commencing on this week.