You could further personalize your site by using a custom background image. You can also choose a different color as your main motif. You can add css codes for those color changes on
Asteroid Options -> Custom CSS. I’m afraid I don’t have much advise on creating a portfolio website.
I am pretty new at creating websites and VERY new to WordPress
I don’t know if you’re aware of this but editing theme files is not recommended. Whenever a theme is updated, all of its files are replaced with a new one so all modifications are lost. https://ronangelo.com/topic/customizing-wordpress-themes/
I noticed you have a flash file hard-coded into where the header is supposed to be. You could have easily accomplished this by adding your code on a text widget then placing it on the header widget area.