We are trying to update the heaters in our house and currently have baseboard heat and were going to use the Cadet wall heaters. Currently all the heaters in the house are on 1 breaker (10 baseboard) is that safe should we split them up as we update?

Yes, depending on the size of the breaker. 10 may be overdoing it.
Add up all the watts and divide by voltage. Usually 240v. You must be at least I believe it is 10% under that rating.
If you have 10000 watts adding all the heaters together and the voltage is 240v (measure to be sure).
10,000/240 = 41.6 amps. Must use a 50 amp breaker. The second problem is wire size. A 10 ga. Wire will only do 30 amps, 12 ga will do 20 amps.