The ones I get on Chess.com might be a bit advanced for you, although I don’t know if they are scaled to your playing ability.
But if you just Google “Chess tactical puzzles for beginners“ there are tons of free online options.
It’s also really important you learn the basics of positional Chess, such as in the opening putting your pieces into desirable squares, developing your pieces quickly, taking control of the center, putting rooks on open files, etc.
Tactical puzzles will help you in recognizing patterns that win material or force checkmate.
By the way, I’ve been playing for years and I often get tunnel vision, just focusing on my own plans without stopping to see what my opponent is up to. That struggle is real. You’re not alone. Once in a while I have to remind myself to stop and try to figure out what my opponent is up to. It’s even worse if I have a strong attack going, because I get so excited and zoned into what I’m doing and I totally missed that my opponent had a strong attack as well.
I'd categorise this thread as me being a chess newbie even though I've played chess on and off for over a year. I've never been able to consistently win games and one of the reasons is the following.
I tend to find sometimes I'll be too preoccupied with gaining a material advantage that I'll miss my opponents aims at trying to checkmate me, and in turn out of the blue (because I haven't anticipated it) I'm checkmated and the game is over even though I'll be up +6 or more points.
I tend to find that I'm ok at analysing my own moves ie thinking, is the square I'm leaving going to be vulnerable or trying to attack my opponents pieces but just don't seem to anticipate opponents check mating me.
How can I become more aware of opponents making checkmating moves? It's really frustrating me and ruining my game. I can determine my own moves without much worry and try to gain material but I miss when opponents make moves against me. How can I improve in this area? Is there some kind of mental checklist I can do after each move I make? I really need help with this.
many thanks
Patrick