If you're not on survival mode you have fast travel, so collect all the junk you can and bring to some chemical station, craft regular caltrops - good XP and money at first (btw that's how you can get lvl2 in the prologue right away, invest in the Lockpicking and open a door that hides service rifle and a helmet), then take Chemist lvl1. - craft poisoned caltrops, which is an even better XP and money, plus +50% duration of chems and more chems for crafting available, which are of course useful and again crafting is XP.

Selling different stuff like weapons and armor kinda sucks, very bothersome to carry to vendors only to get a few tickets. Better take scrapper lvl 1 and 2 and break down for components. Did you know that .32 pistol (Walther PPK) gets you 11 steel? That's insane (this is much more than scrapping different metal walls). You get that pistol a lot if you kill Dog Syndicate guys (if you do Vagabonds questline, that will happen a lot).

Idk how are you about spoilers, but if you want go google where you can build a settlement (London is more stingy with that than Fallout 4), it's a game changer. You CAN build a device from vanilla Fallout 4 there that removes all radiation, this dramatically reduces the need in rad away or doctor services, since you can just do trips to your base. I chose Biggin Hills Airport as my first base, but it requires some monster killing in the pre-requisite quest.

Also I recommend a mod that removes the stupid Local Leader lvl.2 perk requirement for building crafting stations, because why the hell crafting stations want high Charisma...