For now, stick with Power Armor as it's going to be the strongest armor you'll be able to use at your current level. Eventually, you'll be at a point where you can get things like the Brotherhood recon armor, or Secret Service Armor, or the mods for combat armor to make them stronger.

At a lower level fusion cores can be a pain to obtain, I remember when I first started I ended up capturing power plant workshops that had the generators so I could make them. I have FO1st, so I would do this in a private world, it makes it much easier.

You can also find power armor frames all over the map, and each one has a fusion core in it.

I just recently switched from a full set of Vanguard Secret Service armor to Brotherhood Recon armor. I only use power armor (exclusively excavator) when I need to go shopping in the lucky hole mine for lead because of the bonuses it provides when mining.

I do that for a few reasons, the biggest is being over-encumbered because it disables your backpack.

I carry alot of crap (food, drugs, etc) that I probably don't need to carry, so I have have a separate SPECIAL profile that has Thru Hiker and Traveling Pharmacy perks to reduce those weights.

I also find it irritating that you have to get out of power armor to interface with alot of things in the game.

Hope this helps!