Firstly i am a beginner on webpages, i have a problem with my wordpress site. I had a website on godaddy : nerfednerds.com, i decided to change it to wordpress with same domain. When i google nerfednerds.com the old version opening ( old version's link is : https ) but my new site is http. I dont have a ssl certificate right now. I mailed to google about index but they said it is about my host and ssl certificate. I want to ask that, if i buy a ssl certificate my new version will be https and when i googled nerfednerds.com it will open?
Yes, you need to make your new WordPress site https by getting an SSL certificate.
Google indexes sites in its own time -- nothing is immediate with them. But, once you have your SSL installed, you can speed things along by getting your site verified and submitting your new WordPress sitemap in Google Console.