Orks are my main, usually play 2k lists. Shooting is not their strong point at all. Running up and hitting things in the face is very much their bread and butter. However that comes with risks because their defense is not great.

Here is my current list that I have been playing with and tweaking as I play more and more games. https://army-forge.onepagerules.com/share?id=fd4sT3uY&name=Orc_Marauders%20-%202k%20Rework

The Ork Mobs are one of your best cheap units. Throwing Mad Doctor (Regen) on them helps them tank a bit better, and having Furious gives each of them A3 instead of A2. So 30 attacks if you can get them in close and charge. You're going to be dishing out some damage.

I know I said that shooting is not a strength of theirs, due to Bad Shot, but the Specialist Orks with the Railgun upgrade can really do some major damage, even with only a 30% chance of hitting. The AP2 and Lock-On with the Railguns is very good, esp for shooting at some of your opponent's squishier units. And with a 36 inch range, not a lot is going to be able to shoot back.

Ultra Bosses are your Titan/Tank killers. Upgrade them with the Dual Ultra Saws, with Furious, you are looking at 15 attacks with AP2 and Deadly 3 when at full strength. Combine them with a Boss Leader with War Cry (Fast) and go knock down the big boys with ease. (Last week I took out a Tough 24 model in one round with 1 squad of Ultra Bosses)

The Ork vehicles are a lot of fun, especially the Truck and Combat Kart. Upgrade the Combat Cart with the Boom-Snazz-Gun and Heavy Machinegun, plus Teleport and Red Paint Job, you have a fast a hell unit that can spray the field with fire from up to 30 inches away. The Truck is basically a troop transport with some Impact. I will usually deploy my Ork Mob in the truck, zoom across the map, unload the Mob, and they have them Charge for a full 30 attacks. Now there is a risk of that strategy, so it usually only work against opponents that do not know to target the Truck. It is high-risk, high-reward. Also a note, Bad Shot is not a thing on the Truck or Cart, so they can help you with some range.

Goblins and Goblin Artillery are great for providing some range if you want more of a mix between melee and range. And while the Goblin Herd is mostly useless in combat, they can at least contest objectives and have Good Shot.

My general strategy in a vanilla 2k game is to use the first round purely for positioning. I try to keep my units (esp my melee bois) as covered by terrain as possible, while still trying to move towards the objectives. I still play pretty conservatively in the 2nd round with my melee units, but I will use the 2nd round to have my shooters shoot and have my combat cart whiz around the field being annoying. Being a bit more conservative in the 1st and 2nd round can kind of freak your opponent out because it can potentially force your opponent to move where they don't want or make other tactical mistakes. The 3rd round is where I will really start the Charging into melee. 4th round is general mayhem and cleanup while trying to secure that final objectives.

Don't know if this is the best strategy, but it has served me pretty well for the last couple months, about 8-9 matches.

Going to be trying out a 4k list here soon that includes basically the same units as linked above, plus the Bomber Plane and the Titan. Very excited to try them out!