Hello everyone. I have finished a page. and wanted to ask if you have a idea to get upto 90+ in mobile and desktop in Google Pagespeed Insights. apart from minimizing the pictures.
This question also is largely outside the bounds of what "should" be asked in this forum, at least if someone wants an answer to a question as broad as this is.
One really needs to get information about a whole range of factors, especially for the purposes of SEO -- optimizing page speed is just one aspect of this goal.
And to further what Aussie said, this would be something outside the scope of BSS. You can go to Google for information on anything that they expect for page speed as well as many other apps and sites out there that can help with that.
Although advice of this sort is outside the realm of what is typically given in these forums, I will throw you a bone...
1) Get rid of all the inline CSS styles. This massively bloats the code and slows down page loading. All your CSS should be in (preferably) a single, minimized stylesheet.
2) If possible, get rid of all the unused classes in your bootstraps.min.css file. Bootstrap is a bloated framework to begin with, so it's never going to give optimal performance on mobile devices, but if speed is really crucial, it's worth doing this. But you REALLY need to be careful and know what you're doing so you don't remove classes that may be used overtly, or in js, etc.
3) Ditch the meta keywords. Search engines don't use them anymore (they haven't for many years now.)
4) You've got useless duplication in your code. For instance, why is this line appearing five times in a row, identically, before the links to your CSS?
<link rel="icon" type="image/png" sizes="970x390" href="/assets/img/MEINEZEIT.png?h=fbb058619714134c2308f8939f7a9dff">
5) Follow the tips that are given on the page speed insights page itself. It's more or less tells you what to do to speed up page loading.
You've also got some obvious SEO mistakes (two H1 tags, missing alt tags on images, poor use of keywords in your text and headings.) Not that I'm in the market for website services, but if I were, the first thing I'd do is check out the quality of the website representing the company I'm considering hiring. If I see obvious errors, I'm going to pass them up. I highly recommend you read this guide, and then re-read it about ten times (which is what I've done) so you learn all the SEO basics by heart.