How to learn the Queen's Gambit Declined

I know I just asked about the Dutch but also I'm thinking I should probably have a safer opening response to d4 as well, also as a French defense player I like the e6 d5 structure. What's the best way to get started with the QGD? Any videos you'd recommend to begin with?

first you have to decide which type of qgd you want to play. i assume you want to stick to those that strongpoint d5 instead of taking on c4 later, but i could be wrong. in any case, here are a few of my ideas.

the tarrasch with e6 d5 c5. it is very open and usually leads to black having an isolated d pawn. you only rarely get this in the french as probably the nd2 lines are the ones that lead to iqp positions, but if you like to play different pawn structures this is good.

the classical one. d5 e6 nf6 be7 nbd7 00 (h6) b6 bb7 and eventually c5 and or ne4. this is closer to the french structures with locked pawn chains. also doesn't require many move order gymnastics.

the lines with a6. so d5 e6 and a6 or first nf6 and then a6. quite recent and new so you could carve your own path here. also i don't have a name for it.

these three i think you can get most of the time. all others have specific move orders so are more avoidable. i don't expect my opponents to cooperate so i would rather play something that is good even when they don't. 

The QGD doesn’t have to be your safe option, you can use it to play for a win as well.  Kasparov has a nice set of videos to get you started. Chess.com also has lessons on the Carlsbad structure since you’ll probably see that a lot as well.

Comment 2 is right in the fact that the QGD comes in many flavors.  Not just in which variations to play, but in how to get there as well.  I don’t care for some lines after d4 d5 c4 e6 nc3 Nf6, so I usually either play be7 on move 3 or use the Nimzo move order.

I just mean, I want to learn the Dutch, but it doesn't appear to be the most solid opening, more like attacking, and then I should have something else that's more solid.

To be fair, the Stonewall Dutch is very solid (as its name implies), and doesn't have to be played for a kingside attack.

Hanging pawns has made a series of the different lines of QGD, you'll find the introductory part here: https://www.youtube.com/watch?v=CMy65JeSShw and all of the lines from the same channel. I suggest you also have a look at the Catalan as White can choose that by playing 3. Nf3 instead of 3. Nc3.

Fair enough. If you're just getting started you should play around and see what type of pawn structures you like to play.  Different variations are known for IQPs, hanging pawns, etc.  

Some variations might also fit better with your repertoire.  For example, if you play the triangle system and your opponent ducks the noteboom you can transpose into a stonewall without dealing with anti dutch systems.