How could I have won this drawn game?
at move 5 you gave up your white-squared B to early, 8 Qxd8+ forces him to give up castling or the e5-pawn, this is where you could've gained an advantage.
20...Rd8! looks strong for Black.
the rest seems well played.
19. Re1 allowing black to trade the rooks when you have to recapture with your knight is bad. It takes your knight away from the center.
" You kept on trading. It is ok."
Unless it gives you a tangible benefit, it is usually best not to seek out trading pieces. It's better to activate all of your pieces.
I think I played fairly solidly throughout, but I never found that little piece of inspiration that turns a match. Where could I have gained an advantage? Did
I have one I didn't know about at any point?
Strategically I see a few misteps with how you played this game.
- one at move 14, to protect a pawn you move your knight backwards.
- again at move 19 you moved your Knight backword to swap rooks when you could have used your rook.
- Forward progress is always better strategically.
- You also had a free Rook and missed it at move 35. That would have guranteed you the game.
In short; swap less, and only for a strategic advantage, while making forward progress.
3.Ba4 The Ruy Lopez is the most explained in any opening manual. It has many variations.
If you can get the black squared bishop to the king side (1.Bg5) pinning a knight, then 1......h6 2.Bh4 g5 3.Bg3 would create too many weaknesses for black. But, remember that the pin will be stronger if black had already castled king side. The case is same for o-o-o.
Other good moves were explained by other members. To be a good player you must look for every possible moves and then analyse each move.
Nothing wastes time like time wasting.
Well Played. Good Luck.