Cheap OPKs Vs Expensive

Hi everyone, January made a year since I came off my bc pills. I am 22 turning 23 next month and ready to take ttc seriously. My fiancé and I have not really stressed the testing but I have used numerous apps to track everything. We figured if it happened without testing that’s great but so far nothing. I want to take this step by step because I don’t want to initially spend a lot of money on tests until I learn what works for me. I need opinions on if OPKs from Dollar Tree are ok to use and results are comparably good to more expensive name brand tests. If not, can you tell me what brands that aren’t super expensive are good to use? I know that this is something to take serious and I will eventually start buying in bulk but I want to find a brand I like before taking the risk of ordering so much at once. I also have seen people using apps to take pictures and log their OPKs and HCGs, any recommendations on what apps are good for that? I have followed these for a while, but I feel like I still know nothing so any recommendations that will help me get my BFP are so appreciated! Thank you guys in advance!