Originally Posted by ChrisSlicks

If it felt like a brick wall trying shift into first (no grind) then this just means that you had the clutch held in for too long before trying to put it into gear. If you hold the clutch in the input shaft stops spinning which can make it difficult to select a gear. Typically all you have to do is take your foot off the clutch and leave the transmission in N and but you foot back on the clutch again and it should engage no problem. If it was grinding then definitely get that checked out.