What is the best startegy to Rank Affiliate marketing Site in Google First page ?

I can suggest you guest posting and creating backlinks for Off page SEO. You can take the help of a tool called Postifluence for this. This tool will surely help you rank higher with its excellent features. It will help you to find the top ranking guest posting websites and bring high-quality backlinks from there. You must try this tool. It is very helpful.

Recently Google has changed its algorithm and So many affiliate marketers complained their website traffic is dropping.

I checked https://developers.google.com/search/docs/advanced/guidelines/affiliate-programs and said it clearly that it needs a unique and helpful article. Most affiliate marketers copy and paste the same article from an affiliate website which Google doesn't like. So first you have to create unique and helpful articles that your audience like.

Share product videos but not from the affiliate sites. Test the product and make videos and images to share with your audience.

Make a group or forum with your loyal customer or audience.

keep up to date with your article. Google like fresh content always.