Can anyone please tell me what stabilizer i should use when embroidering basic t shirts and polo shirts?

Iron on tear away stabilizer as well as the appropriate number of layers of normal, tear away stabilizer. Depending on the amount of stitches you may need 2 or 3 layers. You do not need Solvy on top.

I use the polymesh cut away. I also use a fusible between the garment and the stabilizer to keep it from stretching. Sorry, I am not home to see the brand of this fusible stuff.
I found it on the web. It is fuse and tear.
/www.sewforless.com/item/WunderStitch_Fuse_N_Tear_Embroidery_Stabilizer_9in_x_12yd_Roll_INCLUDES_10_FREE_EMBROIDERY_NEEDLES/3628/c404