If the problems affect the whole site, consider a rebuild. If they’re limited to the page your ads will send people to, fix that page. If the offer, inquiry path, and tracking already work, you can start a campaign.
Consider a redesign if visitors can’t tell what you sell, key pages are hard to use on a phone, or contact options break across the site. Fix the structure and inquiry path before paying to send more people there.
If a campaign promotes one service, give it a page that matches the ad, explains the offer clearly, and makes it easy to call or submit a form on a phone.
If visitors can understand the offer, use the page on mobile, and get in touch, test the campaign. Verify tracking before launch so you can tell which ads generate inquiries.
Can a new visitor explain the offer? Is the page easy to use on a phone? Have you tested the form, call link, or booking flow? Does the right conversion register when you test it? Can someone follow up on inquiries?