Being new to the game, I would advise against it. Heavy cav makes for a VERY expensive attacking unit, with a provision cost of 6 and a high iron cost, you don't want to be continuously recovering losses in your first village of such a valuable defensive unit.
There are several choices or options you can explore and I will gauge them from safest to riskiest (in my own opinion)
1. Build pure defense, makes you a very unfeasible target for most players and then with your first noble take a barbarian village next to you for offense and build pure offense. You might even take 2 villages to build a second defense if you are worried.
2. Find a partner, either in your province, or one close to you in the next province and form a partnership, one builds defense and one builds offense. One becomes the hammer and one the shield, the offense player would help the defense player take their first village while the defense player supports with defense. Once you both get growing your start up deal turns into coordination as you both build Offense and Defense villages. N.B Be sure to have level 5 statue for cross province coordination, to ensure you fight at full strength.
3. Build mixed village. 50% Off and 50% Def, this will provide SOME defensive capability though obviously not as strong as it could be while your defense shares time and resources with your offense. This is risky because you become slightly more feasible as a target, and your offense loses the power it would in the same way, so you would be looking for an easier target also.
4. Pure offense, risky as a solo player with little experience, you are dependent on being the fastest grower in your province and first to strike those around you with efficiency. With no defense, you are a nice target for a player that can reach a point to damage you if you can't get to them first.
