Should i make backlinks for subpages for different topics? My site is insurance and it covers many different types so should i start creating backlinks for the other pages with links on those keyword?

Will this also help my page rank and placement for the homepage on google?

Yes, you can defiantly make back link from your website sub pages. You can use link building technique with your sub pages keyword. Use ethical way and start to make your sub pages back link. This technique is helpful to increase your sub page ranking on targeted keywords for sub pages. Back links are good for website whether it is for home page or for sub pages.