If you are looking for requests in the base game only (for the Jack of all trades achivement) here is my Day 1 guide on the matter:
https://steamcommunity.com/sharedfiles/filedetails/?id=2952090377

(6x spinels)
In Chapter 2, where the door with the buttons is, you'll find the first request of the dlc as you are walking up to see the third sign to open the door. All Four Medallions can be shot from the platform you are currently standing on.

First is hanging where the sign is

For the next ones, just turn back from the edge of the platform
The second is hanging from the bottom as you are going back to the door
Third one is right above the last one, in a little corner

The last one is right under the platform you were on all this time, you can shoot it when you come back to the door you were supposed to open.

(5000 pesetas and 7x spinels)
This request asks you to sell a jacket to the merchant. It is available at the entrance of the factory at chapter 3.

Its a zombie that has it. The jacket is very similar to the one Leon wears in the game so you will spot it in no time. Just kill the zombie and sell the jacket to get your reward
This is the zombie with the jacket

(7x spinels)
Contract is in chapter 4, where the merchant is after the bottles puzzle
i took that one before taking a screenshot im sorry
All 5 medalions are in the garden area of the castle. Make sure to clear the area before starting so u dont get annoyed by all the ennemies in that part

First one is in front of you when coming in the garden

Second one is on this facade to the left of where you shot thje first medalion

This one is at the middle again, on the broken wall on top of where you came in

Once you collect medalion #3, go to the left and check out the cage (where you first meet the dogs in the base game) a medalion will be waiting there

Finally, the last one is on one of the towers where you gotta raise the flag in the base game at the right of the garden

(8000 pesetas and 8x spinels)
This contract is located in front of the merchant in the canal, he will ask you to kill the "monster of the canal" You can access this area after lowering the water and progressing through the story

The fish is located in this little cave, just crouch and kill the big fish. He is friendly and will absoluetly not hurt you

Pick him up and sell him to the merchant for your reward.

(8x spinels)
This one is pretty hard if you arent aware of it, just make sure to follow the screenshots and u should be fine


After opening the pillars moving inside the cave, you can shoot the first bug from the center

Right behind the stairs to the facade, you can shoot the second one
*Someone told me i shouldve added more precision to this one. It is right behind the main staircase you use to go to the facade of a castle, right before going down the elevator to the island
Screenshot credit to Paramenides

Directly on the facade, you can shoot the last one

(24000 pesetas and 10 spinels)
This next request will be in the regenerators area, you will need the thermal scope to get it!
Contract is at the merchant before, as usual
You will need to find two scarabees

The first one is in the room with the "compounts". The scarabee is inside the regenerator to the left once you vault the window

Last one will be found in the dissection room

(9 spinels)
This is probably the hardest one by far, you will need to shoot 3 bugs, like the fifth one, except its in the area where you get shot by turrets and spammed by enemies :D
Request is at the merchant right before this section.

Once you enter the zone, the first bug is to your left (watch out for the turrets you see)

Once you get out of the pit, and progress through the zone, you'll see the second one on the tower

Keep going to the left and you can find an angle on a cliff. Use the thermal scope if you cant find it. This one is pretty hard so you might need the sniper

Took me a long and painful afternoon but thank you for reading and using this guide :) if you have any feedback please comment on this guide, i read every comment and reply to the constructive ones! Check out my other guide on RE4R for the rest of merchant requests for the achivement !