New web site replacement "Google" considerations?

I am replacing my existing https web site with a new site. Several of the existing menu pages are no longer relevant and are being replaced. The site did not attract much interest and google and others rarely visited because I did not have an htaccess file directing to the HTTPS site. Once I got that corrected more robots are visiting and more pages indexed. This month so far is a huge increase. So I want to minimize the impact of search engine visits with the new site if at all possible. I do not get much direct traffic per GA.

Is there anything that I can do to minimize the impact of the change? I do have a 404 page.

The new site will be primarily photos and video content. I have a large portfolio on Adobe portfolio ( because of ease of use with LR) but I do not believe they are indexed. I do have a GA code on that site. I am planning to link the new site’ collections (a subset of the AP site) to link to the respective Portfolio collections. Would this link help SEO? Would linking to my Adobe Stock account help SEO?

Any help / ideas would be appreciated.