You can only keep a player who was on your roster at the end of the season, and who spent at least 5 consecutive weeks on your team. Keeper status is provided to the player, not to the team, and is based on when they were drafted, not when a team acquired them.
Keeper League formats involve fantasy teams getting to keep a handful of players from year-to-year. This maintains a fair amount of quality in the draft pool from year-to-year, however, from a gameplay perspective, it's very unsatisfying.
If you're talking about one keeper and a more or less standard league, selecting a QB is probably unwise, unless it's Luck or Rodgers, and even then it's a gamble.
Keeper leagues are right in the middle. Each season has some bearing on the next. Managers don't carry over their entire rosters but also don't start from scratch each year. In keeper leagues, managers select some, but not all, of the players from their previous season's roster to “keep” into the following season.
Keeper leagues allow Team Managers to keep players on their roster over multiple seasons without having to redraft them. Keepers are only available in League Manager leagues. Team Managers may select as few players or as many players as the league creator selected during league creation.
While Draft Pick Trades is on, a new "Draft Picks" section appears and you'll be able to select a draft pick from next season while selecting your desired players to trade. Each trade needs to have an equal number of items traded (like 2 draft picks for 2 draft picks).
A keeper league functions similarly to a redraft league, with the added twist of keeping a fixed amount of players on your team from season to season. With keeper leagues, fantasy managers gain multi-year benefits for their successful draft picks, while still avoiding significant penalties for their bad ones.
Definition: A Keeper player is defined by being drafted in the prior season and being on a roster the entire season. If a trade has them travel to a new team, that is fine but if this player was dropped to waivers and picked up by the same team or a different team, he is no longer an eligible Keeper.
Evaluating Your Keepers Each Season Consider factors such as age, injury history and team context when making your decisions. It's also essential to weigh the costs of keeping a player, such as draft pick sacrifices or salary cap penalties, against their potential value.
RB, RB, WR, WR/flex, WR/flex, flex/te/qb(earliest I would take QB), then bench players and any starting spots that aren't filled. Draft 1 QB (unless you like someone as a lottery pick), and you don't have to draft kicker or defense (pick up whichever of those has the best matchup each week).