I just made my first video..I'll just share my expeirence...i have a shitty old xp laptop too..
I was reccomended Sony Vegas too from this forum..I "downloaded" it.. thinking "how tough could it be"..i work with technology all day and am decent at graphic design and photoshop...after many $%#&(@(@#%ing tries to figure it out and constant freezing because of the old computer I said $%# it. the preview would never work so i had to render the vid just to seee it. If your computer is slow using movie maker there is NOO way u can run sony vegas.
I used windows movie maker and created exactly what i wanted.. all i wanted to do was combine clips, slow down/speed up sections, add titles and credits, add music, and some transitions/effects..
here's the vid
https://vimeo.com/55673382
If it is your first video editing try I would reccomend keep using windows movie maker..its idiot proof and does all the basics..
sony vegas is very confusing for a beginner (like myself) and very slow on shitty machines.
just my 2 cents.. i know alot of people here love sony vegas..but for me..it simply was not the right program... maybe once I buy a new comp and learn some basic editing..i also had a sony vegas professional teaching me some basics and it was still confusing as fuck..learn on a basic program
EDIT: sorry I was too lazy to read everybody else's replies..so this post is purely based off the OP's post
EDIT 2: the video in the link took me about 3 hours to make in windows movie maker ..just FYI.. I spent about 10 hours in sony vegas and didnt get it anywhere near close to being presentable