Adjust size of H1 & H3 tags located in Style.css of WP. Also Captcha plugin needs fixing or change out.

Hi, When I create a new posting on Wordpress and begin to ad the H1 and H3 tags, the letters in those sentences are giant. I wish for those letters to be the same size of the rest of the blog. I wish for whatever i pick to be the H1 or H3 tag all letters remain regular size, not giant. I was told to change the H settings it must me done in the [login to view URL] file. Can you set all those tags to the same regular text size of my website so i can now ad H1 and H3 tags to all the past and future postings and pages? Wp template pics the post title to be H2 automatically and im ok with its large size. I think it should pick by default the post title to be H1 dont know why wp does that. Now For the second job. I like using "really simple captcha" plugin , but it only works for about 3mins or less and stops working.. I dont know why, i called my host, no help. can you fix this or find and set up a nice small simple captcha to my site that is like really simple captcha? Please be honest about both jobs if you can do them or not. The last guy i hired off this net work lied to me about experience and i hired him afterwards he didn't understand what im asking although i asked him the same job descriptions above, thank you for reading! please see the vid,, are you experienced with this? <[login to view URL]>