Upgrate Dell Optiplex 3050

In order to help you the exact form factor of your system is needed. That is whether you have a micro, SFF, or tower system. The specs vary depending on your form factor.

As mentioned by JOcean, your upgrade plan would be depending on which form factor you have.  In general, Dell propriety designs have limited your upgradeability.  Here are my thoughts.

1.  RAM 32GB with correct specs will work with down clock to 2133/2400

2.  PSU 650w won't work with OEM drop-in.  It will required some mod or to sit outside and will required appropriate adapter cable.

3.  GPU GTX 1650 will work with mini tower and 240w PSU

4.  M2 1tb PCIe SSD will work

just to add to JOCEAN and chino contributions, you can use Dell oem 360w psu to power gtx 1650 in a 3050 tower. The 360w psu is a direct drop in and fits like a glove.

user validated 2x16 gb memory for 3050. confirming chino that 3050 memory spec Non-ECC dual-channel 2400MHz DDR4 SDRAM. (Memory performance on Intel® 6th generation processors will be at 2133MHz).  So the 3200 mhz included in list below will run at 2400 w your i3-7100.