Hi Ramirez,
Pfiew, that's a difficult question about recommending an envelope generator, there are so many. What you could consider is to start easy with one Doepfer A-140, it's effordable and I had tested it (together with quite a few other Doepfer modules) and it's a good module. I like the touch and feel of Doepfer modules, but that's of course a personal impression, Doepfer might not be everybody's cup of tea; but then again, that's applicable for every brand I guess :-)
Just start with one A-140 module, get some experience with that and if you feel you need another envelope then you still can consider another brand or just get a second A-140 module next to it.
A few more envelope generators I am keeping an eye on (but that doesn't mean other brands and types are not good or shouldn't be considered, it's just my personal opinion, so far, it might change over time too). Here some ideas and this is certainly not a complete list:
Doepfer A-135-4C, A-140, A-143-1, A-143-2
2hp - ADSR
ADDAC - 506 - VC Stochastic Function Generator
Erica Synths - Black Dual EG/LFO, HADSR EG, Black VC EG
Intellijel - Dual ADSR
Make Noise - Contour
Malekko - Quad Envelope
Pittsburgh Modular - ADSR Mk II
Qu-Bit - Countour
WMD - Multimode Envelope
Xaoc - Zadar
This is just a "small" and quick selection (my list is larger but it doesn't make sense to display that here) however there are so many more ADSR modules, you really have to look and decide for yourself what you need and want, it's close to impossible to give you here a good and correct advice; other than the option of perhaps start with a simple but good ADSR A-140 from Doepfer.
Kind regards, Garfield M.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads