How to choose right wordpress theme?

I am building a Kids related site to be used both parents and kids. I dont know how to choose right wordpress theme. I searched thousands of wordpress themes but as I dont know much basics its hard for me to decide what to choose.
Questions I have;
I want three column site like https://family.go.com/entertainment/article-mm-77587-10-fun-outdoor-games-for-kids-t/ or https://fun.familyeducation.com/play/outdoor-activities/33394.html and want three coloumns as
a) Left bar will have categories, popular articles, tag cloud etc + box with adsense ads.
b) Middle one will have my articles + adsense links at the bottom plus link to next article in that category.
c) third one should be wide ( like in above links) and will have box with adsense ads and affiliate ads.

This is basic setup what is in my mind. It can change little bit based on feedback and circumstances. Now, to achieve this,
– Do I need adsense ready theme?
– Can I add any plugins like TAG CLOUD etc to my lef side bar?
– Can I insert adsense/affiliate ads anywhere in the blog or need to do something to make it ad ready?

Can I achieve all of above with wordpress and if yes, what should I look while choosing a theme?

I have selected few themes based on what is available but all say fixed width column ??

Can I achieve all the above if I use following theme?
https://www.wpskins.org/testrun/index.php?preview_theme=6442
https://www.celebrific.com/gossip-city-wordpress-theme-release/
I dont really like them as there are not too many kids related themes available.

Regards, Satinder
PS: Before moving to wordpress themes, I was trying to use #5 Template in the first row at this link (neoneon) https://www.bravenet.com/webtools/template/ or partially visible at https://misssmartypantssite.com/ ( not my site, I googled it). But I am told that it wont work with wordpress.