FWIW here's a couple of walls I did at home, no great problem. Mine are under 900 tall so all that is required is a compacted roadbase footing and drainage behind. The wall has been there for for two winters now and has not moved an inch. Here is an
installation guide to give you an idea of the construction technique.
A wall like this is simple to construct provided you don't deviate from the instructions layed out by the manufacturer.
A neighbour, over the road from me, built a wall from the same blocks. He chose to ignore the manufacturers instructions regarding footings, drainage and reinforcing mesh. He put his wall up in a fraction of the time it took me, and it fell over after the first heavy rain.