Increasing "holdings" means accumulation, no dump involved since the purpose is to increase your stash. It's fine if you sold it but to be able to acquired it again, basically you need to buy it.
You know it's really difficult for newbies to understand the fundamentals the simple term of "buy low sell high method". But believed me, once you continue to do trades, you will be able to understand what is that all about.
You don't need any article or videos. Just used your common sense and read stuffs on the internet. You can do your own analyzation. Just be serious. Goodluck,