Ofc, feel free to use whatever method fits you

All I know about painting is from youtube, there are great tutorials, here are some:
skink:
https://www.youtube.com/watch?v=XYodFF87Ruw
saurus:
https://www.youtube.com/watch?v=YA_WPKbZwPM
Plus, there is a GW how to paint guide, wich goes through the basic techniques on various models. You can find a backup copy on [har-har]bay,cr
There are many more videos on youtube, but to get familiar with the basics, just spend this ~2,5 hours on watching these vids.
In my opinion, its is best to start painting on a medium sized model, like a kroxigor, its not too detailed and it has not so many tiny parts wich are the hardest to paint (according to me), you can try out everyting on this guy.
Also, painting does require patience, precision. Dont bother if the painting goes slowly, with practice it will speed up.
Cheers, looking forward to see your jobs
