RDCraft

Just find out how to play it yourself. It's more fun to just use your gamer tuition!
Just kidding since it's not allowed for me to not state any information about the modpack. 
I'll just tell you the starter information. Now this modpack IS NOT RLCRAFT, BUTTT it does have similar aspects to it. Just like in RLCraft you have to get flint. You can acquire flint from Gravel. After that go right click the flint on stone. Proceeding that go destroy some leaves to acquire sticks. After accomplishing that you can get a flint knife by putting the two together in your inventory crafting grid. Use the knife to get 3 plant fiber. Once accomplishing that change the plant fiber into plant string. If you acquire all of those materials you can FINALLY make a axe to destroy a tree.
In-game tips.
You can press H to open up your health points. You'll pretty much die to absolutely everything unless you get the proper amount of heart crystal shards to make a heart container. You can consume the Life Container to get a extra heart.
After reaching level 5 you can press L to unlock a skill tree that'll make this mod pack a little less terrible. Once you've reached the proper amount of experience points you can unlock new skills to make certain things easier, for example you can do a extra 10% damage via unlocking one of the skills in the mod pack. You can also get ore prospecting which doubles a certain number of ore.  (mostly vanilla ore)
That's the most i feel like I should share with you all. It would be better for you to learn everything for yourself. If you have any suggestions for making the mod pack a little extra difficult or there's a bug or thing you don't like maybe i'll go into the players perspective and remove them. Thank you for playing the mod pack.