opening

which are the easiest opening for white and for black to study? Tks

Stafford Gambit for black and Reti Opening for white

Easiest for white is probably the London system, the Caro-Kann is not overly theoretical for black and puts you in a fairly good place positionally. My view is that your opening theory should excite you and get your opponent to play your game rather than his/hers. I'd need a proper idea of your playstyle to recommend any opening theory.

@ilgulla said in #1:
> which are the easiest opening for white and for black to study? Tks

Colle system for white, the theory is easy to learn.
Caro kann and Slav defense for black

"... A beginner should avoid the Queen's Gambit and the French Defense and play open games instead! While he may not win as many games at first, he will in the long run be amply compensated by acquiring a thorough knowledge of the game. ...
... A position is called open after some of the center pawns have been exchanged, so that the pieces command open lines. The openings beginning with [1.e4 e5] are more apt than others to lead to open positions, since as a rule [d4] and exchange of center pawns will follow. On the other hand it is obviously more difficult to carry out the move [e4] after [1.d4], inasmuch as the [e4-square] is originally unprotected. This is the reason why [d-pawn] openings as a rule lead to closed positions. ..." - Richard Réti (~1929)
www.amazon.com/Masters-Chessboard-21st-Century-Richard/dp/1936490218

traps at the beginning level are usually best, but they won't grow your chess skill. so be prepared and know a few, but don't make them their repertoire. solid e4 is best and e5 Is great

Study everything & Never look for the 'easy' way in life' by Studying COMPLETE GAMES you get the Openings, Middlegames & endings . You will also receive Tactics in the form of Direct Attacks & Counterattacks . I can fully recommend Chess Videos by GM Igor Smirnov & Three Chess Books to Start you off & on the way @ilgulla ... Logical Chess Move by Move by I Chernev, Capablanca's Best Chess Endings in 60 Complete Games by I Chernev & The Art of Logical Thinking In Chess by Neil Mcdonald . You will have fun Learning so much Chess with the Videos by Smirnov free on You Tube along with the 3 Chess Books that will take you less than a Month each book while playing Chess on Lichess

I really like simple openings like for white with the system of 1. Nf3, g3, Bg2, O-O and for Black the Caro-Kann defense and the Benoni Defense (and I would consider these to be simple for me, at least) ! I enjoy playing these openings but I really do believe they differ from playstyle to playstyle, you should figure out what openings you like to play depending on your playstyle and if you enjoy playing open, closed, sharp, positional, tactical positions! :)

I can't say which opening is easiest to study as I really don't know. I suspect no one does.
What I can recommend is one book that has helped me at different times in the past. How to Open a Chess Game by 7 International Grandmasters has advice from different perspectives. Each makes different recommendations. From Petrosian, I got interested in the Torre Attack, from Larsen I got interested in the Vinken System (Grand Prix Attack). And from there, I got interested in other opening systems, I learned to branch out and explore new territory. And of course to respect the individual POV of great masters.
This is the thing. As @ThunderClap says, study whole games, because there is so much to learn about so many different aspects of chess. Start with what interests you now, and explore the opening(s) that take you along the path you wish to follow. At least for a while. But sooner or later, a time will come when you choose another path to follow. It's all good, as long as you are learning.

"... It is illogical for one who has not earned his master title to ape the complicated opening variations played by, say, a world champion. After all, while the opening is indeed important in chess, it is still only one part of the game; victory can be found as well in the middlegame or endgame. Your only task in the opening is to reach a playable middlegame. ... How should we lay the foundations of our opening repertoire? It is hard to come up with a single answer to satisfy every player. Individuals will have different objectives in the opening, as well as different playing strengths. Nevertheless, to all players I can recommend the following: simplicity and economy. These are the characteristics of the opening systems of many great masters. They do not strain unduly for advantages in the opening; they would just as soon move on to the next phase of the game, hoping their skill will overcome the opponent in the middlegame or endgame. ... the most complicated variations demand huge amounts of time for home analysis, time available only to professional chess players. ... I will discuss here only openings and defenses that in my opinion offer simplicity and economy. ... The Dragon and Najdorf Variations ... have been analyzed to twenty moves and more; if a player without adequate preparation walks into an analyzed sequence he may lose even to a weaker opponent. Under no circumstances should you handle these variations in serious games unless you are a professional chess player with unlimited time for study. ..." - GM Lajos Portisch (1974)