Ok try this (this is what I did). Try using the same move over and over to "condition" your opponent (like always run and dash attack). Then after about 5 or so, use a different move because when you're running at them they're expecting a dash attack, so you can just grab at their shield or run behind them and pivot grab if they always spot dodges the dash attack, etc.
Basically try to memorize "read" what your opponent does and how they space every move you make against them. Then find the right strategy to go against it like grabbing more or charging smashes when they will dodge, etc.
It might take a while but when you play just try to remember what people do, like when they lay on the ground after they get hit, they usually roll away or get-up attack, so just follow their roll and punish or shield their attack etc. (I see you do this one at least, but only for get-up attacks).
If you think all this takes too much work, just play defensively the whole match, don't approach and have them come to you, and try to 'read' how they approach you so you can pivot grab, shield, etc. Like walk backwards and have them follow you, then forward smash behind you or dash at them and grab, etc.