Before you embark on amp building, firstly you must only have the mentality that is just a hobby project. Prepare to spend time, effort and many cash on it.
If you have no experience in electronics at all, go and try some kits first. Like the cheapest 2 LED flasher circuit. These you can get for like under $5 for a ready to assemble kit. Next, you have to learn to fabricate everything from scratch, without kit. Just the parts, use hardwiring or vero board to create the circuit. One rewarding circuit is a 10LED chaser, using 1 logic IC & one timer.
Basic theory is essential, if you want to get anything right. By which it's at least a 2weeks (14days) course for the average IQ person.
Lastly, electronics also require talents, like only few individuals out of 1000 will seem to take to it like ducklings to water. Just like music or sports n everthing else.