Can attempting to cannulate a vein and missing be bad ? it ended up in a big lump and bruise, will it be ok?

Vein puncture : It will most likely be ok. Use cold compression a couple times a day. If it persists after 4-6 weeks you might want to see a physician.

Hematoma: It seems that you had bleeding following the vein puncture. The blood gets trapped around the vein and under the skin. This results in usually a black and blue mark which over several days will turn a yellow color and then resolve. It could also get hard for a few days. Wet heat to the area will help it to resolve. This is not serious.