changing joomla urls to wordpress urls

hi,
I have a one year joomla site and now i want to change my cms and also categories.for not losing search engin rank,i should do redirection.
I should say,i dont want to change my domain name.but i want to change category.
right now,articles in my joomla site is : Joomla url is : https://www.mysitename.com/category1/subcategory1/article.html
but as i want to change category in wordpress,the categoris and sub categories changes to this :
https://www.mysitename.com/category2/subcategory2/article.html
now help please with this 2 :
1) how to redirect that no problem happen ?
2) Does changing the CMS affects my rank , although if i do redirect

Thank you very much