Should I sell tokens right after I got it from campaign?
if the campaign payment is part of the distribution then YES regardless of what that token is.
it doesn't matter what token because as soon as the distribution is done, specially when they give a lot of it away it means there will be a lot of it (a huge supply) in the market. even if a small percentage of the people having those tokens decide to sell (which they will) the price will drop initially. selling fast means you get the higher prices.
then if you are really interested in that token and think it can rise up, you can simply buy back at the bottom.
you are right sir, if we sell at the beginning of the coins in the share we will get a higher price, as you said, we analyze whether it has the potential to rise or not, my experience always sells at the beginning of the coins in the share but 1-3 weeks ahead the price rises 100% even more. not all tokens can be like that, some are down and prices do not go up anymore. so after experiencing it I only sell half a token and hold it until the coin rises again, I think that's the safest way