As a “slow davener”, I regularly have this issue. I generally try to show up early. When I don’t show up early, I peek at the clock after Baruch Sheamar and evaluate what to say from there. I usually daven at Litvish Kollel with with a Yekkish RK, so you can set your clock to a 7:32 Yishtabach shimcha. One time, it happened at 7:34 and the everyone in the shul looked like it may well have been an hour late. Knowing your minyan is important.
Before PdZ:
the important things are all the brachos, first verse of shema, and korban TAMID. You can skip most other stuff.
PdZ:
At a bare minimum, you should be saying Baruch Sheamar, Ashrei, and Yishtabach. If you find you regularly have time left over, add the five Hallelu tehillim. The important thing is to NOT RUSH. When you rush, all you’re doing is depriving yourself of actually learning the davening. Focus on one verse at a time, then add more as you become more fluent.
When in doubt consult a competent rabbi, who you can trust to give you the right answer for you.
Mazel tov on your growth. It gets besser.