This is a helpful list of locations in Red Dead Redemption 2 with their respective coordinates, which should be useful for teleporting with trainers and for use in other mods too.
If you have not unlocked Blackwater/New Austin, teleporting to these locations will cause the game to attempt to kill you.
Mid-Eastern Locations
Coordinates
Emerald Ranch Fence
1417.818, 268.0298, 89.61942
UFO Cult House
1469.529, 803.9516, 100.2565
Rhodes
1232.205, -1251.088, 73.67763
Rhodes Sheriff Station
1359.575, -1301.451, 77.76775
Braithwaite Manor
1010.883, -1741.42, 46.57271
Caliga Hall
1748.701, -1373.015, 44.07471
Saint Denis Locations
Coordinates
Saint Denis Entrance
2209.557, -1346.319, 45.27962
Saint Denis Police Dept. HQ
2519.439, -1309.522, 48.98456
Cornwall Freight
2327.491, -1502.421, 46.15683
Saint Denis Paperboy
2683.755, -1401.467, 46.36121
Saint Denis Post Office
2747.493, -1403.775, 46.19331
Schiffer Brewery
2626.123, -1219.239, 53.24075
Holdern Barber
2663.265, -1182.402, 53.18868
Theatre Raleur
2531.462, -1271.88, 49.19459
Park Gazebo (Dominos)
2520.084, -1250.082, 50.04138
Milliners (Clothes)
2552.014, -1176.577, 53.31112
Dr. Joseph R Barnes MD (Doctor)
2725.046, -1240.167, 49.9267
Kuo Chao and Co (Guns)
2724.051, -1283.323, 49.40885
Horner & Co General Store
2819.6, -1311.311, 46.73164
Saint Denis Trapper
2831.333, -1227.615, 47.64871
Saint Denis Fence
2849.29, -1203.049, 47.69022
Doyle's Tavern
2792.439, -1176.049, 47.94577
Marcel Beliveau (Photography)
2734.564, -1111.322, 48.8867
Fontana Theatre
2683.063, -1365.809, 47.4687
Sisika Penitentiary
3348.683, -638.0975, 44.96677
North East Locations
Coordinates
Van Horn
2983.451, 430.152, 51.17512
Van Horn Lighthouse
3034.831, 434.7511, 63.76253
"Better than my dog" Crashed Boat
3587.617, 1412.362, 41.64929
Annesburg
2904.366, 1248.808, 44.87448
Annesburg Mines
2811.514, 1350.152, 71.40891
Willard's Rest (and Waterfalls)
2962.592, 2206.051, 165.286
Doverhill (Tesla Coil)
2528.707, 2289.215, 176.5532
Ambarino Sign
1977.036, 1782.974, 191.9578
Veteran's Homestead
1695.536, 1517.756, 146.7541
Northern Locations
Coordinates
Grizzlies Train Station (Bridge/Large Waterfall)
571.4683, 1709.609, 187.5573
Barrow Lagoon
-1022.5, 1682.607, 242.1601
Mount Hagen
-1504.352, 1246.987, 313.6848
Frozen Couple
-1596.308, 1838.178, 299.4427
Grizzlies Camp (Tutorial Area)
-1343.558, 2425.952, 307.4015
North West Locations
Coordinates
Monto's Rest (Building Camp)
-1389.252, -235.0196, 98.85808
Fort Wallace
361.913, 1461.297, 179.1987
Valentine Sheriff Station
-278.2138, 807.0493, 119.38
Strawberry
-1731.426, -412.8995, 154.8678
Strawberry Sheriff Station
-1809.933, -349.4936, 164.6563
South West Locations
Coordinates
Tanner's Reach
-2370.176, -1595.122, 154.0966
Swadlass Point
-2573.16, -1371.534, 149.7127
Upper Montana River
-2003.783, -1058.096, 77.02795
Manzanita Post
-1962.67, -1614.491, 116.0338
Native Attack Site
-2037.57, -1917.054, 110.0583
Macfarlane's Ranch
-2333.056, -2350.935, 63.20446
Roots Chapel
-3322.755, -2833.409, -6.234455
Armadillo
-3665.947, -2612.442, -14.08434
Benedict Point
-5245.899, -3470.671, -22.09243
Tumbleweed
-5517.375, -2936.821, -2.219434
Rathskeller Fork
-5165.079, -2143.5, 11.77453
Ridgewood Farm
-4823.544, -2711.381, -13.74694
Mercer Station
-4352.891, -3052.94, -11.10614
Fort Mercer
-4217.854, -3514.639, 36.98927
Gaptooth Breach
-6000.769, -3319.31, -21.72198
Off-land Locations
Coordinates
Guarma Beach (Shipwreck Beach)
1997.57, -4499.807, 41.77455
Guarma Fort
999.9134, -6749.735, 63.12267
Unfinished or Out-of-bounds Locations
Coordinates
Greenery (Unfinished Map)
285.4689, 3279.318, 284.6352
Large rockbed (Unfinished map)
729.1184, 3606.849, 254.0442
Edge of the Universe (Unfinished Map with Endless Ocean)
898.1358, 4093.001, 286.8478
Sand Mountain (Unfinished Map)
4260.696, 3583.581, 45.7186
Underwater Trees (Unfinished Map, SPAWNS ABOVE WATER)
4456.247, 2491.354, 40.23709
Beach
4235.684, 2051.991, 43.71272
Floating Forest (Unfinished Map, SPAWNS ABOVE WATER)
5650.821, 423.6956, 161.0469
Gaptooth Breach Mineshaft (Unfinished)
-5980.294, -3119.834, -31.03055